III.

Dr. Pringle's Paper read after Dr. Whytt's Letter.

Read April 21, 1757.

DR. Pringle begs leave to inform the Society, that having read the copy of his letter, within these few days, to Dr. Shaw, Mr. Hawkins, and Mr. Graham, those gentlemen found his account agreeable to their several observations; only Mr. Graham took notice, that, of late years, Lord Walpole, in his journies to Norfolk, had twice voided some blood with his urine, but with little uneasiness; and that at other times had passed some sand and stony particles (tho' never larger than the head of a small pin), attended with frettings of the parts, scarce painful. But Mr. Graham was not sure, whether these accidents were prior or subsequent to the sequel of the case, communicated to the Society by his Lordship.

Dr. Pringle thinks it may be likewise proper to acquaint the Society with another circumstance in Lord Walpole's case, which he had both from Dr. Shaw and Mr. Graham, viz. that after using the soap and lime-water for some time, his Lordship was freed from a very obstinate dry and scurfy eruption, which had resisted several other medicines. But as there were no marks of a putrid scurvy (that species expressly alluded to towards the end of Dr. Whytt's letter) the Society will easily understand, how the lithontriptic medicines may be prejudicial to one troubled with the true putrid scurvy (such as is most incident to sailors) and yet not be improper for those, that are subject to the scurfy eruptions, which are commonly, tho' erroneously, called scorbutic.

Pall-Mall, 20 April, 1757.

XXVII. An Account of the Virtues of Soap in dissolving the Stone, in the Case of the Rev. Mr. Matthew Simson. Communicated by John Pringle, M.D. F.R.S.

To the Rev. Tho. Birch, D.D. F.R.S.

SIR,

Read April 28, 1757.

A Few days ago I received from Dr. Austin, physician at Edinburgh, the case of the Rev. Mr. Simson, drawn up by himself, in the form of a letter to Dr. Austin; and which you may remember was alluded to by Dr. Whytt, in the paper read at the last meeting of the Society.

As I am at liberty to communicate this account to others, I thought it would not be unacceptable to the gentlemen of the Society, to have another well-attested instance laid before them of the virtues of soap in dissolving the stone, or, at least, in removing all those painful symptoms, which usually accompany that distemper.

To the patient's own narration I have subjoined an extract from Dr. Austin's letter to me, containing the sequel of the case from the date of Mr. Simson's letter to his death; with an account of the state of his bladder, as it appeared to Dr. Austin upon dissection. I am,

SIR,
Your most obedient humble Servant,
John Pringle.

Pall-Mall, 27 April, 1757.

A Letter from the Rev. Mr. Simson, Minister at Pencaitland, to Dr. Adam Austin, Physician in Edinburgh.

Dear Sir,

Read April 28, 1757.

ACcording to your desire, I send you the history of my case; which is as follows:

I was of an healthy constitution till the year 1730, when I was seized with a frequent inclination to make water, without any previous pain in the kidneys or ureters. This symptom continued till the year 1733, without giving me much uneasiness.

In June 1733, as I was riding from Edinburgh to my own house at Pencaitland, I was seized with a great difficulty and pain in making water, which went off when I got home.

In the month of July, having again got on horseback, I was seized with the same complaint, but more violent; for then some drops of blood came away. From this time, if I rode eight or ten miles, I passed some blood, but without pain.

In September I made a journey of 60 miles on horseback; but every two miles was obliged to dismount, and made some bloody water.

I continued much in the same way all the year 1734, as the preceding; only had one additional complaint, of a pain in the glans after making water, and likewise in the neck of the bladder. The only thing I did for it was, to drink plentifully of warm milk and water; and gave over riding, on account of the bloody urine.

In the month of August I was sounded by my nephew, Dr. Simson, professor of medicine in the university of St. Andrew's; but he found no stone, which he attributed to a wrong posture I was in, when he sounded me.

During the winter, if I walked more than usual, I was sure to have a return of the bloody urine and strangury.

In November 1735, I was sounded by Mr. Balderstone, surgeon, in Edinburgh, a gentleman very expert in that operation, and likewise by Dr. Drummond of Perthshire. They both distinctly felt a stone: and I myself took hold of the catheter, when it was in my bladder, and felt the stone as distinctly, as if it had been in my hand.

About Christmas I was seized with a pain along the left ureter, and violent vomitings; but, upon using a turpentine clyster and opiates, it went off.

During the year 1736, I continued much the same as the preceding year, always drinking great plenty of milk and water; which gave me great relief, as to the bloody urine.

I was advised by my nephew, Dr. Simson, to go to London, and be cut by Mr. Cheselden; the rest of my friends advising me to be cut by Mr. Smith, a lithotomist at Perth. However, I deferred the operation, and continued much the same all the year 1737, having severe fits now and then.

In the year 1738 Sir Alexander Gibson, of Addiston, informed me, that he had been in my condition, had passed several small stones, and had found incredible service from the use of soap pills: for, from not being able to get out of bed, in the space of two months after using the soap he was able to go a hunting. However, for some time I was afraid to try the soap, not knowing what effects it might have on a confirmed stone; Sir Alexander Gibson's case being only that of small stones. But the Rev. Mr. Lundie, of Salton, by experiments convinced me of the efficacy of soap in dissolving a confirmed stone out of the bladder; for the stone gradually grew smoother and smoother, and at last was quite dissolved.

On the 12th of February 1739, I first began the use of the soap, and in the beginning took only a drachm in the 24 hours. The first week it made me a little qualmish: however, I gradually increased the dose; so that in six weeks I took six drachms a day, without its disagreeing in the least with me. I made it up into pills, and washed them down with a draught of warm milk and water.

From the time I began to use the soap, my gravelish symptoms gradually abated; but, upon walking two or three miles, I made bloody urine. However, that symptom gradually abated; and in the year 1743 all the symptoms of a stone quite vanished, insomuch that I could walk, ride, or go in a machine, as well as ever.

From February 1739, to July 1743, I took every day five or six drachms of soap: but after that time I diminished the dose to half an ounce; and never after had any return of a gravelish symptom, tho' I still imagine the stone is not intirely dissolved; for after sitting some time, I find as it were something come to the neck of the bladder, but which gives me no uneasiness.

This, Sir, according to the best of my memory, is my case: and if it can be of any benefit to you, in the cure of this painful disease, it will give great pleasure to,

Dear Sir,
Your most obedient Servant,
Matthew Simson.

Nov. 20th, 1749.

The Extract from Dr. Austin's Letter to Dr. Pringle.

Read April 28, 1757.

THE Rev. Mr. Simson's letter to me as written in the year 1749; about which time he told me, that he had ridden 40 miles in a day, without any bad symptom ensuing.

In the year 1752 he broke his thigh-bone at the neck; by a fall from his horse, and continued for six weeks in great pain; but after that time he grew easier, and was able to put his foot to the ground. One day, as his servant was helping him to walk across the room, he let him fall; upon which Mr. Simson felt a severe pain: the broken leg became then evidently shorter than the other; and by that misfortune he was confined to his bed for near two years. However, about six months before he died, he was so well recovered, as to be able to go to church, and to perform divine service.

About the beginning of May 1756, Mr. Simson was seized with a diarrhæa, which resisted all medicine, and carried him off in the 83d year of his age. From the date of his letter to his death he had never discontinued the use of the soap (except during the time of his last illness), tho' he had not been troubled with any painful symptom of a stone since the year 1743.

I obtained leave of his friends to open the body, but found no stone or gravel in the bladder; that part appearing to be, in every respect, in a natural state, except at the neck, where the coats seemed to be schirrous, and were about a quarter of an inch thick.

It is probable, that the stone had been of a softer texture, and more easily dissolved, than ordinary; otherwise five or six drachms of soap taken daily, even for so long a time, could not have dissolved it intirely; for many have used that medicine in much larger doses, and at the same time have drank lime-water plentifully, without obtaining such effects; tho' all their painful symptoms were removed by that course, as Dr. Whytt has shewn in his treatise on this subject.

I shall only add, that Mr. Simson's son, who is now minister at Fala, was present at the opening of the body, and can attest, that there was no stone found in the bladder.

Adam Austin.

Edinburgh, 15 April 1757.

A Letter from Dr. Adam Drummond to Dr. Adam Austin, relating to the Rev. Mr. Matthew Simson's Case. Communicated by J. Pringle, M.D. F.R.S.

Read June 23, 1757.

I Have yours; and was present when Mr. Balderstone sounded Mr. Simson; and both of us perceived, very distinctly, a large stone: and Mr. Simson himself felt it; which we were the more sollicitous he should do, as he was sounded before by Dr. Simson, who had declared there was no stone. But the particular magnitude of it we could not well determine at the end of a long catheter; tho' I remember Mr. Balderstone, who was well versed in that business, conjectured it to be pretty large. He was sounded only once by us, as the urethra was a little hurt by turning the catheter. There is only one circumstance in the case, which Mr. Simson seems to have omitted; that, from the first symptoms of the stone, he passed a great deal of mucus mixed with pus, as well as blood; and great quantities of gritty red sand, all in single grains, never any concreted into small stones. I take the more notice of this, as I do not remember, that, after he used the soap, he ever passed any sand, but a good deal of mucus, in which the soap was discoverable by its frothing. Could the gritty particles of sand be again suspended in the urine, so as to become invisible? or were they wrapt up in the soapy liquid, so as to escape observation? I have seen several stones of a soft consistence dissolved into mucilage by soap: but the sand passed by Mr. Simson, before he used the soap, seems to indicate his stone of a harder nature, tho' indeed it felt obtuse at the end of the catheter.

I shall rejoice, if many instances of this kind are found afterwards: but this seems to be the only one yet, of a stone in the bladder being dissolved by soap alone. I am,

Dear Doctor,
Your most humble Servant,
Adam Drummond.

Bandeeran, June 5. 1757.

XXVIII. An Account of the Impressions of Plants on the Slates of Coals: In a Letter to the Right Honourable George Earl of Macclesfield, President of the R.S. from Mr. Emanuel Mendes da Costa, F.R.S.

My Lord,

Read April 28, 1757.

I Have the honour to address this letter to your Lordship, in order to be communicated to the Royal Society, if your Lordship deems it worthy the attention of that learned and illustrious assembly.

The impressions of various kinds of plants are frequently, I might say always, found in some of the strata lying over coal; but more particularly in a stratum of earthy slat, which, in my History of Fossils, page 168. Species IV. I have synonymed Schistus terrestris niger carbonarius, and which always lies immediately upon the coal-stratum, not only in the coal-pits of this kingdom, but of many other parts of Europe, e.g. France, Saxony, Bohemia, Silesia, &c.

Most of these impressions, my Lord, are of the herbæ capillares et affines, the gramineous, and the reed tribes: but, however, among them many rare and beautiful impressions undoubtedly of vegetable origin, and impressed by plants hitherto unknown to botanists, are not unfrequently met with.

Besides these, my Lord, found over coal-pits, there are likewise found in some parts of this kingdom, as at Robinhood's-bay in Yorkshire, Coalbrookdale in Shropshire, &c. many curious impressions of the fern tribe in regular nodules of iron-stone; and, in the latter place, not only impressions of plants, but even the cones or iuli of some kinds of trees are met with, very perfect and fair, and curiously imbedded in masses of iron-stone.

Philos. Trans. Vol. L. Tab. V. p. 229.

J. Mynde sc.

The most part of the impressions of ferns, grasses, &c. are easily recognizable, they so minutely tally to the plants they represent. Others indeed, tho' they do not exactly answer any known species, yet have characters so distinctly expressed, that they are easily arranged under their respective genera[139]. Therefore I shall not trouble your Lordship with any further remarks on all such, but shall only touch on those elegant and extraordinary impressions, probably of unknown vegetables, above-mentioned: for that they are the parts and impressions of vegetables, I think clearly evinced, if we attentively and with a philosophical mind consider them, and reflect on the various circumstances, which attend them in the places, where they now lie buried.

I have therefore the honour, my Lord, to exhibit the drawings of seven such extraordinary impressions, and the fossiles themselves, for your Lordship's and this learned body's inspection (See [Tab. V].). The impressions figured Nº. 1. is from Mr. Mytton's collieries at Drilt, near Oswestry, in Shropshire; as are also those figured Nº. 2, 4, and 7: they are found sometimes two feet in length, and are generally covered with a thin crust of coal. The specimina Dr. Woodward exhibits, Catalogue B, pages 106, 107. specimina q. 22. and q. 32. are analogous to this, tho' not exactly the same. The Doctor's fossiles were from Haigh in Lancashire; and he imagines the impressions to be made by vegetables of the fir kind. Volckman also, in his Silesia subterranea, tab. 22. fig. 2. figures a branch with a rhomboidal work on it, and with three long narrow leaves, which seems akin to this impression.

Nº. 2. seems of the reed tribe: the knobs placed in rows, which are like the vesicles on the quercus marina, and some other algæ, are very remarkable. Woodward, Catalogue B. page 9. specimen a. 1. exhibits an impression akin to this, which he imagines to be of the fern kind.

Nº. 3. from a coal-pit in Yorkshire. I cannot but think this impression is owing to somewhat of the fir kind. Dr. Woodward, who exhibits such a like impression, Catalogue B. p. 16. specimen a. 108. imagines the same: his words are, “The impression is much like what might be made by the branches of the common fir, after the leaves are fallen or stript off.”

Nº. 4. seems to be of the same kind as Nº. 2.

Nº. 5. This extraordinary impression is from Mostyn-colliery in Flintshire. It is a little obscured; but, when attentively viewed, exhibits a reticular impression, the meshes whereof are rhomboidal hollows, and the sides of the rhombs, or the net-work, are raised, or in relief.

Nº. 6. is from Newcastle. Volckman, ibid, part 3. tab. 4. fig. 9. seems to be of this kind.

Nº. 7. The same author, Volckman, figures a somewhat-like impression, ibid. fig. 5.

Only these seven extraordinary impressions I have presumed, my Lord, to treat of at this present time; but I have many more in my cabinet equally curious, some few of which I here exhibit to the Society, without taking any further notice of them: only I shall add, that many extraordinary impressions occur in Woodward's and other collections, and many are iconed in authors, worthy the attention of the curious.

These impressions, my Lord, are not only met with in small pieces; but large evident branches, some feet in length, have been found. I have, in the collieries of Derbyshire, frequently traced branches with (what seemed to me) long narrow leaves proceeding from them, and parts of other vegetables, above a foot's length: but the hardness of the substance they are immersed in renders it impossible to get them out without breaking them to pieces[140].

As these remains of vegetables are very extraordinary, I would recommend to the curious in botany to take notice of them, as an Appendix Plantarum adhuc incognitarum. For my part, I am so very little skilled in botany, that I hardly presume to offer my opinion; which is, that they are impressions and parts of species of the firs and pines, of the tithymals, the cereus's, and other arborescent plants, and of large reeds; for some of the said kind are embellished with ribbed, studded, and reticulated works; e.g. the Hercules' club, or rubi facie senticosa planta Lobelii, described by Dr. Grew, Museum Reg. Soc. p. 221. the cerei, &c.

I further exhibit to the Society some few specimina of iron-stones with cones or iuli imbedded in them. These, my Lord, are from veins of ball iron-stone, in the lands of Lord Gower, at Okenyate, a village on the Roman road of Watling-street; and from the iron-works at Coalbrookdale in Shropshire. The cones are frequently met with in fragments, but rarely so intire, and are never found but in the strata of iron-stone. I have added to these a figured fossile body, much like a cone, found sometimes in our chalk-pits in England, but chiefly in the pits at Cherry-Hinton in Cambridgeshire. Dr. Woodward, Catalogue B. p. 22. specimen b. 72. calls them cones seeming to be of the larix; and imagines they were not come to ripeness or maturity. They certainly have some resemblance to cones, tho' I much doubt them to be so; but they most exactly resemble the roots of the cyperus rotundus vulgaris of botanists.

I shall finish this paper, my Lord, by acquainting your Lordship and the Society, that I firmly believe these bodies to be of the vegetable origin, buried in the strata of the earth at the time of the universal deluge recorded by Moses. It is, I must confess, with regret, that I find there are some, who reject the burial of these bodies at that fatal catastrophe, but substitute partial deluges to account for it. Did those gentlemen consider, or maturely weigh, the many remarkable and strong evidences of an universal deluge, every-where obvious in the bowels of the earth, they certainly would abandon their imaginary system: for, my Lord, it is not only the immense quantities of marine remains, dispersed in all terrestrial strata, which are to be considered (that circumstance alone might give some reasoning to their system of partial deluges), but the following more weighty circumstances are likewise to be added and flung into the scale. 1º. The heavings, displacings, trappings, and breaks of the metallic veins, and the loads of rubble, met with at vast depths, and where no marine remains were ever found; and such heavings, &c. are not rare in metallic or mineral works: of which, to give your Lordship an idea, I have presumed to sketch the following plan of such a phænomenon.

These cross-loads are not unfrequent in the mines on North Downs, near Redruth, in Cornwall. Wheal-Widden copper-work there, in 1750, was about 60 fathoms deep. The load was 20 feet over; and has many cross-loads two or three feet over, which sometimes heave the metallic load from one to five or six fathom. These cross-loads are generally filled with fragments of stone, minerals and other rubble.

2º. If these effects proceed from local deluges, recedings of the sea, gulphs atterrated, &c. we should then indeed find marine remains: but how will that account for the vast quantity of remains of terrestrial vegetables and animals, equally met with, and in like manner as the marine remains, in the bowels of the earth? And, 3º. Were local or partial deluges the cause, we should then find only the animals and plants of the climates or places, where such deluges have happened; whereas in these fossil remains it is quite the contrary: the remains of those plants and animals, we know, are of animals and plants, the inhabitants of the most remote climes from those, where they now lie buried; e.g. the rhinoceros-bones, in the cave called Baumans-hole, in the Hartz Forest in Germany; the strange bones in the Antra Draconum in Hungary; the horns of the moose-deer, and other prodigious horns, and elephants bones, found in England, Ireland, Germany, Sibiria, and even America, &c. of vegetables, parts of the arbor tristis in France; bamboo's, or great Indian reeds, frequent in England; with numbers of other such examples. And of those remains even of the marine shells, yet unknown to us, all appear exotic to the climes where they now lie deposited; e.g. the cliffs at Harwich in Essex abound with a species of buccinum heterostrophum, and other shells, never yet discovered in the adjacent waters. The ammonitæ of so many species, and the innumerable variety of conchæ anomiæ, with which this island abounds, are yet unknown to be inhabitants of our seas, and appear exotic to this climate. Therefore, my Lord, I reasonably conclude partial or local deluges could never have produced such effects. However, unprejudiced to any opinion, if the learned, who favour the system of partial deluges, will either confute these my assertions, or give solid reasons for the facts alleged to be producible by local deluges, atterrations, &c. I will joyfully embrace the truth: but till then, my Lord, I would recommend to those systematical gentlemen, not to pervert that excellent maxim of the great Lord Bacon, and, instead of Non fingendum neque excogitandum, sed inveniendum quid natura faciat, aut ferat, not to corrupt it into fingendum atque excogitandum, non inveniendum quid natura faciat, aut ferat.

I am, with great submission and respect,

My Lord,

Your Lordship's
Most devoted,
and most obliged,
humble Servant,
Emanuel Mendes da Costa.

London, 27 April, 1757.

XXIX. A Catalogue of the Fifty Plants from Chelsea Garden, presented to the Royal Society by the worshipful Company of Apothecaries, for the Year 1756, pursuant to the Direction of Sir Hans Sloane, Baronet, Med. Reg. & Soc. Reg. nuper Præses, by John Wilmer, M. D. clariss. Societatis Pharmaceut. Lond. Socius, Hort. Chels. Præfect. & Prælector Botan.

Read April 28, 1757.

XXX. Remarks on the Opinion of Henry Eeles, Esq; concerning the Ascent of Vapour, published in the Philosoph. Transact. Vol. xlix. Part i. p. 124. By Erasmus Darwin, M.D. Communicated by Mr. William Watson, F.R.S.

To Mr. William Watson, F.R.S.

SIR,

THE inclosed papers were designed for the perusal of the Royal Society; being an endeavour to confute the opinion of Mr. Eeles about the ascent of vapours, published in the last volume of their Transactions. But the author, having no electrical friend, whose sagacity he could confide in, has at length prevailed upon himself to be so free to send them to Mr. Watson; to whom the world is so much indebted for the advancement of their knowlege in electricity.

Whence, Sir, if you should think that these papers have truth, the great Diana of real philosophers, to patronize them, you will confer a favour upon me, by laying them before that learned Body. If, on the contrary, you should deem this confutation trifling or futil, I hope you will be humane enough to suppress them, and give me your objections; and by that means lay a still greater obligation on one, who has not the pleasure to be personally acquainted with you. From,

SIR,
Your very humble Servant,
Erasmus Darwin,
Physician at Litchfield, Staffordshire.

March 23. 1757.

LETTER I.

To the very honourable and learned the President and Members of the Royal Society.

Gentlemen,

Read May 5, 1757.

THERE is ever such a charm attendant upon novelty, that be it in philosophy, medicine, or religion, the gazing world are too often led to adore, what they ought only to admire: whilst this vehemence of enthusiasm has generally soon rendered that object contemptible, that would otherwise have long laid claim to a more sober esteem. This was once the fate of chemistry: the vain and pompous boasts of her adepts brought the whole art into disrespect; and I should be sorry, if her sister electricity should share the same misfortunes. It is hence the ingenious Mr. Eeles will excuse me, for endeavouring to lay before you my opinion on the ascent of vapours, tho' it by no means coincides with that he is so strenuous to establish, and plucks a plume from his idol goddess electricity.

The probability, supporting the hypothesis of Mr. Eeles, according to his own expressions, rests on this: “That every particle of vapour is endued with a portion of electric fire; and that there is no other sufficient cause assigned for their ascending.” (Phil. Trans. vol. xlix. part. i. p. 134.). My design is therefore first to attempt to shew, that another theory, founded on principles better known, will sufficiently explain the ascent of vapours: and then, that some kinds of vapours are not endued with a more or less than their natural share of electric æther.

The immense rarefaction of explosive bodies by heat, depends either on the escape of air before condensed in them, or on the expansion of the constituent parts of those bodies. This distinction has not been sufficiently considered by any one to my knowlege; nor shall I at present amuse the Society upon this head; it being enough for my present purpose to observe, that they may be thus distinguished: where air is emitted, it cannot be condensed again into the same bulk by cold; but the expansion of heated parts of bodies, as soon as that heat is withdrawn, ceases to exist.

Nitre comes under the first of these classes: in detonation it emits great quantities of air, not afterwards condensible to the like space. This may be seen by firing a few grains of gunpowder in an unblown bladder, or in a vessel nearly full of water with its mouth inverted. The same is true of all the solid parts of animals and vegetables, when subjected to fire; as appears from the experiments of that learned philanthropist, Dr. Hales.

But of water the contrary is evident. In the steam-engine, a jet of cold water, we find, instantly condenses that immense rarefaction; which I apprehend could not be, if it was constituted of escaped elastic air. And altho' this steam must be acknowledged to put on some properties of air; such as ventilating a fire; or that a taper blown out by it, is capable of being again lighted immediately, and that without a crackling noise, which occurs when touched with water; this does not in the least invalidate our opinion, tho' it has certainly conduced very much to propagate the former one: since from this way of reasoning, the whole must be air, and we should have no water at all in vapour.

From considering this power of expansion, which the constituent parts of some bodies acquire by heat; and withal, that some bodies have a greater affinity to heat, that is, acquire it sooner and retain it longer than others; which affinity appears from experiments, and which, I apprehend, is in some ratio of their specific gravities and their powers of refraction, reflexion, or absorption of light; or at least in some ratio much greater than that of their specific gravities alone. From considering these, I say, many things, before utterly inexplicable, became easily understood by me. Such as, Why when bismuth and zinc are fused together, and set to cool, the zinc, which is specifically heavier, is found above the bismuth? Why the buff covering of inflammatory blood, the skum of heated milk, the sedative salt of borax, which are all specifically heavier than the liquids in which they are formed, are still formed at the surface of them? How benzoin, sulphur, and even the ponderous body mercury, may be raised into vapour, again to be condensed unaltered? And, lastly, how water, whose parts appear from the æolipile to be capable of immeasurable expansion, should by heat alone become specifically lighter than the common atmosphere, without having recourse to a shell inclosing air, or other assistant machinery? and when raised, I am persuaded we shall find, that to support them floating, perhaps many days, in the atmosphere, is not a knot so intricate, as to oblige us to conjure up a new divinity to unravel it.

But before we proceed to this second part of our task, it will be necessary previously to consider, first, how small a degree of heat is required to detach or raise the vapour of water from its parent-fluid. In the coldest day, I might say the coldest night, of winter, when the weather is not frosty or very damp, wet linen or paper will become dry in the course of a few hours. A greater degree of heat must indeed cause a quicker evaporation. But I am persuaded, that was it not for the pressure of the superincumbent fluid, greatly less than that of boiling water would instantly disperse the whole so heated into vapour.

Secondly, That in the opinion of Sir Isaac Newton, well illustrated by the late lamented Mr. Melvil, the sun-beams appear only to communicate heat to bodies by which they are refracted, reflected, or obstructed; whence, by their impulse, a reaction or vibration is caused in the parts of such impacted bodies.

This is supported by the experiment of approaching some light body, or blowing smoke near the focus of the largest glasses; and from observing, that these do not ascend, it is evident the air is not so much as warmed by the passage of those beams thro' it, yet would instantly calcine or vitrify every opake body in nature. And from this we may collect, that transparent bodies are only heated at their surfaces, and that perhaps in proportion to their quantity of refraction: which will further give and receive illustration from those very curious experiments, of producing cold by the evaporation of liquors, published by the learned Dr. Cullen, in the late volume of Essays Physical and Literary, at Edinburgh. In these experiments a spirit-thermometer was immersed in spirit of wine, and being suddenly retracted, was again exposed to the air; and as the spirit of wine adhering to the glass evaporated, the spirit contained within the thermometer was observed to subside. Now as the difference of the refraction of spirit of wine and glass is exceedingly minute, compared with the difference of refraction of spirit of wine and air; we may consider, in the above experiment, the heat to be communicated to the thermometer only at its surface: but here the adherent fluid escapes as soon as heated; by which means the glass, and its contents, are deprived of that constant addition of heat, which other bodies perpetually enjoy either from the sun-beams immediately, or from the emanations of other contiguous warmer bodies; and must thence, in a few minutes, become colder than before.

The ingenious Mr. Eeles, I dare say, has already foreseen the use I am going to make of this principle; viz. “That the little spherules of vapour will thus, by refracting the solar rays, acquire a constant heat, tho' the surrounding atmosphere remain cold.” And as from the minuteness of their diameters, if they are allowed to be globules, they must do this to a very great degree, I apprehend none of those objections will take place against us, with which Mr. Eeles has so sensibly confuted the former received theories on this subject.

If we are asked, how clouds come to be supported in the absence of the sun? It must be remembered, that large masses of vapour must for a considerable time retain much of the heat they have acquired in the day; at the same time reflecting, how small a quantity of heat was necessary to raise them; and that doubtless even a less will be sufficient to support them, as from the diminished pressure of the atmosphere at a given height, a less power may be able to continue them in their present state of rarefaction; and, lastly, that clouds of particular shapes will be sustained or elevated by the motion they acquire from winds.

I should here have concluded this paper, perhaps already too long; but upon revising it, I find, where the affinity of some bodies with heat is mentioned, that the deductions made from thence are not sufficiently explained to be intelligible. First then, If the power of expansion of any two bodies, by heat, be in a greater proportion than their specific gravities, then will there be a certain degree of heat, in which their specific gravities will be equal; and another, in which the gravity of that, which was lighter when cold, will exceed the gravity of that, which was heavier when cold. Hence zinc and bismuth alter their specific gravities in fusion; some urine, and many solutions of solids, grow turbid as they cool; others alter their colours. Secondly, If (the power of expansion by heat being equal) the power of retaining heat be in a greater ratio than the specific gravities; then, during the time of cooling after being sufficiently heated, there will be an instant, when the heavier body will become the lighter, and swim upon the other. This seems the case in the buff covering of inflamed blood, the skum of heated milk, and the cristallization of some salts: for if these effects were from the evaporation of the thinner parts at the surface, they should happen during the greatest evaporation, or when boiling; but, on the contrary, they are all done in the greatest degree when the liquor has for some time began to cool. Lastly, If the quickness of acquiring heat be in a greater proportion than their specific gravities (the power of expansion being equal), then, during the time of their acquiring heat, there will be an instant, when the body, that was heavier when cold, will now become the lighter. From one or more of which principles, I apprehend, the volatility or fixity of all minerals, and many other bodies, takes its origin.

It is no part of my design to account to you, gentlemen, in what manner such an expansion of the parts of bodies can be brought about by the action of fire. Tho' perhaps a rotatory motion only of each particle on its own center might be sufficient to produce such a rarefaction; and the more so, if such parts were any other figures than spheres, as by the percussion of their angles they must result further from each other. Nor is the existence of such a rotatory motion without some probability, when we observe the verticillary motion given to charcoal-dust thrown on nitre in fusion, or the wonderful agitation of the parts of burning phosphorus, or even of a common red letter-wafer touched by the flame of a candle. But as in this paper I have laboured (and I hope not without success) to shew you, that some properties of solar heat are sufficient to account for the elevation and support of vapours; so in another letter I propose nearly to demonstrate to you, that the electric æther is far from having any share in the production of this important phænomenon.

From,

Gentlemen,
Your very humble Servant,
Erasmus Darwin.

Litchfield, Mar. 20, 1757.

LETTER II.

To the very honourable and learned the President and Members of the Royal Society.

Gentlemen,

Read May 5, 1757.

EVERY theoretical inquiry, whose basis does not rest upon experiments, is at once exploded in this well-thinking age; where truth, under your patronage, has at length broke thro' those clouds, with which superstition, policy, or parade, had overwhelmed her. But experiments themselves, gentlemen, are not exempted from fallacy. A strong inventive faculty, a fine mechanic hand, a clear unbiassed judgment, are at once required for the contrivance, conduct, and application, of experiments; and even where these are joined (such is the condition of humanity!) error too frequently intrudes herself, and spoils the work.

My very respectable antagonist, Mr. Eeles, to whose ear, I am convinced, the voice of truth is more agreeable than that of applause, will forgive me the following critique on his performance; as by that means, I am persuaded, the probability of his notions will be intirely destroyed, and the foregoing theory receive additional supports.

For this purpose our first endeavour will be to shew the uncertainty of some of the most material principles, that support his arguments; and afterwards, the fallacy of the experiments he has given us.

First then, in page 130. Mr. Eeles has asserted, that the greatest possible rarefaction of water is when it boils. I think it might be said, with equal propriety, that the greatest rarefaction of solids was when they began to melt: and this may indeed be verbally true, if we chuse to alter the names of bodies, when they undergo any alteration by fire; so solids take the name of fluids, when they are in fusion; and water the name of vapour, when it is greatly rarefied in the steam-engine. Whence we find this assertion seems to be founded on a confusion in terms, and the fact far from being existent in nature.

In page 133. the sphere of electrical activity is said to be increased by heat. If by electrical activity is here meant an increase of its repulsive power (the thing, which seems to be wanted in Mr. Eeles's hypothesis), I know no experiment to show it. If it be meant, that it is capable of being attracted to a greater distance; I conjecture it may, as the heat will rarefy the ambient air, and we know the electric æther is attracted at very great distances in vacuo; but this cannot properly be called an increased activity of electric fire.

We are afterwards told (page ib.) “that electric fire will not mix with air:” whence, in the succeeding section, it is argued, “That as each particle of vapour, with its surrounding electric fluid, will occupy a greater space than the same weight of air, they will ascend.” In answer to this, it must be observed, that there are some bodies, whose parts are fine enough to penetrate the pores of other bodies, without increasing their bulk; or to pass thro' them, without apparently moving or disturbing them. A certain proportion of alcohol of wine mixed with water, and of copper and tin in fusion, are instances of the first of these; the existence and passage of light thro' air, and, I am persuaded, of electric fire, are instances of the second.

To illustrate this, the following experiment was instituted. A glass tube, open at one end, and with a bulb at the other, had its bulb, and half way from thence to the aperture of the tube, coated on the inside with gilt paper. The tube was then inverted in a glass of oil of turpentine, which was placed on a cake of wax, and the tube kept in that perpendicular situation by a silk line from the cieling of the room. The bulb was then warmed, so that, when it became cold, the turpentine rose about half-way up the tube. A bent wire then being introduced, thro' the oil into the air above, high electricity was given. The oil did not appear at all to subside: whence I conclude, the electric atmosphere flowing round the wire and coating of the tube above the oil, did not displace the air, but existed in its pores.

This experiment I formerly tried various ways, as I had conceived, if the electric matter would displace air, it might have been applied to answer the end of steam in the steam-engine, and many other great mechanical purposes. But as from the above it appears, that the contrary is true, it is evident, that electric matter surrounding particles of vapour must, in fact, increase their specific gravity, and cannot any-ways be imagined to facilitate their ascent.

I may add further, that if this be true, that it pervades the pores of air, its specific levity cannot, by any means I know, be compared with that of air. Its particular attraction to some bodies, at least to much the greater part of the terraqueous globe, is abundantly greater than that of air to those bodies: and hence its gravitation to the whole globe would appear, at first view, to exceed that of air. But the more I consider this, the more perplexing and amazing it appears to me: and thence must leave it to the investigation of my very ingenious antagonist, or some other able philosopher.

I come now to the experiments, that are given us to show all vapour to be electrifed. In these Mr. Eeles seems to have been led into error, by not having observed, that many bodies electrifed will retain that electricity for some time, altho' in contact with conductors. The Leyden phial may be touched three or four times by a quick finger before the whole is discharged. Almost all light dry animal or vegetable substances, such as feathers and cork, do this in a much greater degree: and in general I have observed, the more slow any bodies are to acquire electricity, the more avaritious they are to keep it.

Part of the plume of a feather, hanging to a green line of silk about a foot long, which was suspended from the midst of an horizontal line of the same, about four yards in length, was electrified with a dry wine-glass, according to the method of Mr. Eeles; and, after being touched nine times with my finger, at the intervals of two seconds of time, still manifested signs of electricity, by being attracted at the tenth approach of it.

A cork ball, on the same line and circumstances, after being electrised, was touched at the intervals of ten seconds repeatedly, for seven times, before it was exhausted. The fumes of boiling water were conveyed upon this ball after being electrised; and, after a fumigation for thirty seconds, it shewed signs of electricity, by being attracted to the approaching finger; and, after thirty seconds more, without any fumigation, it again obeyed the finger; and again, after thirty more, but at less and less distances. The same appearances occurred to me from the fumes of resin. From whence I apprehend, that Mr. Eeles, having dipped the electrised down of the juncus bombycinus in vapour for perhaps half a minute (for no time is mentioned), and finding it still retained its electric attraction, was not aware, that this same had happened, if he had by intervals touched it with his finger, or any other known conductor of electricity.

As Mr. Eeles had here objected, that there was no real opposition in the electric æther of glass, and that from wax; the common experiment to shew this was many times repeated with constant success; viz. the cork ball, suspended as above, after being electrised by the wine-glass, and repelled from it, was strongly attracted by a rubbed stick of sealing-wax; and vice versâ. In the same manner I observed the electric æther from a black silk stocking (which was held horizontally extended by the top and foot, and, being rubbed in the midst with an iron poker, was applied to the cork ball), to be similar to that of glass, and opposite to that of wax. But the following experiment appears to me to put this matter out of all doubt, and to demonstrate, that this difference is only a plus and minus of the same specific æther, and not different qualities of it, as Mr. Eeles would suppose.

A stick of dry sealing-wax was rubbed on the side of a dry wine-glass, and a cork ball, suspended as in the former experiments, played for some time between them: but glass rubbed with glass, or wax with wax, did not manifest any electric appearance. Whence it would appear, that in rubbing glass and wax together, the glass accumulated on its surface the identical æther that the wax lost. Nor is this a digression from my design: for if this opposition of the electricity of glass and wax be established, it still contributes to demonstrate the fallacy of Mr. Eeles's experiments.

But what alone would intirely destroy this electric hypothesis, is, that from the experiments of Mr. Franklin and others, the clouds are sometimes found to be electrised plus, sometimes minus, and sometimes manifest no signs of electricity at all. Whence to say an accumulation of electric æther supports these clouds, seems an assertion built upon a very unstable foundation, whose whole superstructure may well enough be termed an air-built castle, the baseless fabric of a vision.

Add to this, that Mr. Eeles, in page 140. tells us, that himself has passed thro' clouds resting on the sides of mountains. Ought not those clouds to have immediately discharged their electricity, and fallen? And common experience may remind us, that any cold bodies will condense vapour, whatever be their electric properties. So mirrors, or the glass of windows, in damp rooms, are most frequently found covered with dew; which, of all other bodies, ought most to be exempted from collecting vapours supported by electricity, as they are the least capable to attract or draw off that æther.

From all which, well examined, I am persuaded, gentlemen, you will be induced to conclude, that tho' clouds may sometimes possess an accumulation of electricity, yet that this is only an accidental circumstance, and not a constant one; and thence can have no possible influence either in the elevation or support of them. I am,

Gentlemen,
Your very humble Servant,
Erasmus Darwin.

Litchfield, March 23. 1757.

Philos. Trans. Vol. L. Tab. VI. p. 255.

The grey Coot-footed Tringa shot near Halifax in Yorkshire (January 1757) and Presented to me by Mr. Thomas Belton Florist of Worley-clough in Yorkshire. Drawn from nature of the Figures of Life by Geo. Edwards in Feb.⁴ 1757.

XXXI. An Account of new-discovered Species of the Snipe or Tringa: In a Letter to the Rev. Tho. Birch, D.D. F.R.S. from Mr. George Edwards, Librarian of the College of Physicians.

SIR,

Read May 5, 1757.

I Take the liberty to lay before you the figure and description of a new-discovered species of the snipe or tringa kind, which was lately shot at Sowerby-bridge in Yorkshire, and sent to me by Mr. Florist of Worley-clough, near Hallifax in the same county. If the account, that follows, shall be thought by you deserving to be communicated to the Royal Society, the real bird, which I have preserved dry, shall be produced at the same time.

This bird is like in shape to most others of the tringa or snipe kind. Its size is better shewn by the figure lying before you (See [Tab. VI.]), than by the dried bird, which is much shrunk since the drawing of it was made. I chuse, by way of distinction, to name it the coot-footed tringa, as it differs from other birds of that genus no otherwise, than in having its toes webbed in the same particular manner as the fulica, or our bald-coot. One of its feet is shewn in the plate, magnified a little, to make it the better understood, in what manner the webs or membranes spreading on both sides of the toes are scalloped or indented at each of the toe-joints. These scallopings are finely pectinated on their outer edges, as the enlarged figure expresses. The hinder toe is small, and finely pectinated on the under side. The bill is black, and channelled on both sides of the upper mandible; in which channels the nostrils are placed near the forehead: it is compressed somewhat like a duck's bill, and ridged along its upper part, as a figure of the head in the corner of the plate may shew. The lower head, figured with it, is intended to shew the bill (which is very narrow) of another species of coot-footed tringa, brought from North America, and described and figured in my Natural History of Birds, &c. plate 46. The eyes are placed farther backward from the bill than in many other sorts of birds; in which the wisdom of Providence is remarkable: for birds of this genus commonly feeding in soft muddy ground on the banks of rivers or the sea, have occasion to thrust their bills deep into the shores, to extract worms and insects; and their eyes would be in danger, were they placed more forward. The fore part of the head, the neck, breast, belly, thighs, covert-feathers withinside the wings and under the tail, are white: the top and hinder part of the head is black. The lower part of the neck behind, and the back, are of a blueish ash or slate-colour, with a mixture of blackish or dusky: the upper sides of the wings and tail are of a blackish or dusky colour: the tips of the covert of the wings are white; the tips of the middlemost or shortest of the quills are also white, and form white transverse bars across the wings. Two or three of the middle quills are wholly white, and all of them have their inner webs white toward their bottoms. It hath twelve feathers in the tail; the outermost of which, on each side, is edged with white. The covert-feathers on the rump, or upper side of the tail, are dusky and white. The legs are bare of feathers above the knees (as they are in most birds, who wade in shallow waters), and of an ash-colour.

I believe no discovery of this bird has been made till now: and it is very probable there are many more species of birds in this island, that have hitherto escaped the notice of curious inquirers. Mr. Ray, in a book by him published, London, 1674. called, A Collection of English Words, &c. with a Catalogue of English Birds and Fishes, &c. after naming the coot in his catalogue of birds, p. 92. says, “Mr. Johnson of Brigna, near Grota-bridge in Yorkshire, shewed me a bird of the coot kind, scallop-toed, not much bigger than a black-bird.” As so little is said by Mr. Ray, one can hardly determine any thing concerning the bird he mentions: and 'tis plain he thought this note scarce worth notice, as he hath not preserved it in the Ornithology since by him published. Nor can I believe it was the bird now before us; for he says it was not much bigger than a black-bird; which implies, that it was something bigger. And, on reading his description of the black-bird, I find he makes it to weigh four ounces; consequently it is four times the weight of the bird above described by me: for my obliging friend, Mr. Florist, who sent me this bird, says in his letter, that, when newly killed, it weighed one ounce. Therefore I am inclined to think, that the bird Mr. Ray has so slightly mentioned, is a bird not as yet fully discovered. I am, Reverend Sir,

Your most humble Servant,
Geo. Edwards.

College of Physicians, Lond.

May the 3d, 1757.

XXXII. Observationes de Corallinis, iisque insidentibus Polypis, aliisque Animalculis Marinis: Quas Regiæ Societati Londinensi offert Job Baster, Med. Doct. Acad. Cæsar. Reg. Societ. Lond. & Scient. Holland. Socius.

Read May 19, 1757.

Domicilium meum mari propinquum[141] occasionem præbet, in nondum satis cognitam quorundam animalium, in mare degentium, generationem et œconomiam inquirendi. Quæ observavi Regiæ Societati temporis successu offerre animus est; sed in hac prima dissertatione tantum observationes quasdam de corallinis, iisque insidentibus polypis, et aliis animalculis marinis, exhibere in animum induxi.

Paucis abhinc annis, inter doctos viros dissensio fuit, utrum corallia, corallinæ, et kerato-phyta veræ essent plantæ, quæ crescunt, et vegetant, in quibus insecta marina nidificant; an vero horum ipsorum essent opus et fabrica. Multi et sagacissimi historiæ naturalis scrutatores ultimam complexi sunt sententiam; sed nemini contradicere studens, simpliciter tantum et fideliter illa referam, quæ variis temporibus in corallinis observavi, et quæ lectorem benevolum, ut spero, convincent, corallinas non magis a polypis fabrefieri, quam diversa fungorum genera ab illis fabricantur animalculis, quibus, æstivo tempore, quasi repleta inveniuntur.

Dura corallia, quæ recenter ex mari extracta, et in rotundum animalculis obsita reperiebantur, primam ansam dedere suspicandi, hæc ab illis esse fabrefacta.

Cum omnia juniora conchylia tenerrimæ et viscosæ substantiæ reperiantur, ex analogia conclusum fuit, parva et tenera animalcula, quæ coralliis insident, æque hæc fabricare potuisse, ac illa durissimas suas conchas et buccina. Sed in historia naturali non tuto ex analogia licet concludere.

Verun quidem est, quod recens natum conchylium tam tenerum est, quam parvus ille corallio insidens polypus; sed tunc concha ejus vel buccinum etiam erit tenerrimum, et quo magis in eo contentum crescit animal, eo major, durior et firmior fit concha: et interior conchæ superficies semper est lævissima et glaberrima, ne tenerrimum animalculi corpus aliquo modo lædi posset, ut in ostreis, mytulis, solenibus, et quibuscunque conchis et buccinis, hoc videre est.

Sed an hoc in coralliis invenitur? Nunquam polypi in ipsa coralliorum substantiâ habitant, sed semper intra hanc et circumdatam corticem. Cavitates, quas in coralliis invenies, non glabræ aut læves sunt, sed asperæ et acutæ. Parvus corallii ramulus nec tener est nec mollis, sed æque durus habita magnitudinis proportione ac maximum: nec minores illi insident polypi quam ramis majoribus.

Cum vero hic, in Zelandia, necdum ulla dura corallia recenter ex mare extracta explorare licuit, me tantum ad corallinas determinare debui, ubique sere prope littora reperiundas, et quibus simillimi, qui coralliis, insident polypi.

Animadvertam tantum mihi videri, animalcula, quæ summas coralliorum extremitates inhabitant, et Nobilissimo Marsiglio flores visa sunt, ad genus etiam polyporum referri debere, et in his extremitatibus non nata esse, sed irrepsisse, dum illas vacuas et domicilio aptas invenerint: eodem certe modo, quo cancelli, quos Bernard l'hermite vocant Galli, vacua irreptant buccina. Et hi cancelli, ut observant piscatores, non casu aut temerarie id faciunt, sed quasi ex consulto. Si sex vel septem cancelli vivi prudenter ex suis buccinis extrahantur, et hæc inter se permixta iis iterum exhibeantur, quisque cancellus in proprium suum, nunquam in alterius buccinum irrepit, et hoc ablatum undique quæritat, quod jucundum visu est.

Necesse mihi fuit quasdam sed paucas corallinarum et polyporum figuras addere: si vero quis plura desideret, elaboratum opus sagacissimi Domini Ellis adeat, in quo quamplurimas et accuratissimas corallinarum et polyporum delineationes inveniet[142].

De Plantis Marinis generatim.

Plantæ marinæ a terrestribus in plurimis differunt, nam hæ in raro aëre excrescentes, nutrimentum suum radicum ope, in terra proserpentium, hauriunt: du millæ plerumque nec radices nec folia habent, sed ex trunco et ramis consistunt. Illa plantæ marinæ pars, qua substantiæ, cui increscit, adhæret, radicis nomen non meretur, nisi quatenus plantam uni semper loco tenet adfixam: sed quod primarium radicis munus est, nutrimentum ei non adfert: ipsa planta per truncum et ramos ex medio, cui semper immersa est, incrementum suum acquirit. Neque maris sundus radicibus recipiendis aptus esset, nam plerumque inconstans et volubile sabulum est, quod continuo fluctuum motu de loco in locum dimovetur, ita ut uno temporis momento radices nudæ, altero sub arena forent sepultae.

Sed quamdiu vera vegetatio marinarum erit ignota, non bene explicari poterit, quare corallia et kerato-phyta, licet ab imo ad summum undique animalculorum cellulis obsessa, læte tamen crescant, ut hoc in plurimis, non tamen in omnibus, observare est. Nam Nobilissimus Marsigli kerato-phyta invenit, quæ nulla cortice, aut quæ uno loco cortice erant obducta, altero non: et corticem hanc non nisi polyporum cellulas fuisse clare ex ejus verbis patet[143].

At rogare mihi liceat, an vera vegetatio plantarum terrestrium, quæ semper nobis ante oculos sunt, bene cognita et perspecta sit? an quidem novimus, quæ vera sit radicum functio, et quomodo hanc exerceant? Nonne plurimæ inveniuntur plantæ, quæ paucissimis instructæ radicibus in altum crescunt, maxime ergo foliorum ope, quæ succos nutritios ex vaporibus in aëre natantibus hauriunt, plantam alunt, et sic radicum defectum supplent. Sed liceat mihi, accuratissimi Bonneti verba adferre; “Plantæ, dicit hic sagacissimus naturæ scrutator, semper sunt sugentes, et in statu suctionis, interdiu radicum ope nutriuntur, noctu foliorum[144]. Sed optandum est[145], quod arte quadam exacte posset determinari, et tunc inter se comparari hanc nutrimenti copiam, quam plantæ radicum ope acquirunt, cum illâ, quæ folia adferunt. Examen hoc forsan nos doceret, quod Aër non minus quam Terra ad plantarum nutritionem et incrementum contribuat.”

Si ergo medium tam rarum et tenue, ut aër (ut ex Celi. Halæi et Boneti experimentis certum est) tantum ad plantarum nutritionem adferat, mirum non est, quod nunquam quiescens et quam maxime heterogenea aqua maris plantas marinas, licet expansis radicibus destitutas, ad tantam magnitudinem, altitudinem et duritiem faciat excrescere. Sed nonne similiter crescunt plurima fungorum genera? Quas radices habent quercubus aliisque lignis increscentes agarici? Quas phallus, elvela, et plura, quæ in Methodo suo fungorum describit J. G. Gledisch.

Hæc de plantis marinis præmittere volui, ut evincam corallinas, licet radicibus careant, crescere, vegetare, et plantas esse posse, ut aliæ terrestres et fungi, quæ similiter aut minimas habent radices, aut plane iis destituuntur.

Cætera, quæ de vegetatione, floribus et seminibus plantarum marinarim observavi, alio tempore indicabo.

De Corallinis.

Corallinæ omnes habent proprietates, quas in genere de plantis marinis indicavimus: Sed præterea, quod præcipuum est hujus dissertationis propositum, omni fere corallinæ, si rami ejus ad justam magnitudinem et firmitatem creverint, tam hyeme quam ætate, animalcula insident, quæ a multitudine brachiorum, et similitudine, quam cum polypis, in aqua fossarum dulci, reperiundis, habent, etiam polypi vocantur.

Si quis corallinæ plantam, eique insidentes polypos, rite examinare studet, non incipiat parvam tenuis ramuli partem in vitro concavo jacentem microscopio inspicere; sed totam corallinæ plantam recenter ex mare extractam in vitrum pellucidum, aqua marina repletum, prudenter inserat: aut talem plantam orbi porcellano concavo in fundo coloris profunde cærulei imponat, et addita sufficiente aquæ marinæ pellucidæ quantitate, ejus ramos prudenter expandat; tunc post quadrantis horæ quietem, illos lente amplificante intueatur, et sic distinctissime in hac unica planta polypos diversi generis, et plerumque mira alia videbit insecta; quæ microscopio dein ad libitum ulterius examinari possunt.

Corallinæ, quæ [146]capillares et filamentosos habent ramulos, aut quæ [147]juniores et tenuiores adhuc sunt, ut

Quae navibus post longum iter;

Aut quæ doliis istis coniformibus, quæ ad littora vel fluminum majorum exitum in mare ad nautarum securitatem ponuntur;

Aut januis emissariorum aquæ marinæ in his regionibus, accreverint, raro vel nunquam habent polypos.

Sed si eadem corallinæ species jam ad sufficientem magnitudinem et firmitatem, et præsertim supra ostrea, saxa, silices, aliaque in fundo maris quiete jacentia corpora, increverit, polypis scatet. Perspicaci suo judicio decidat lector B.

An hoc efficitur, quia polyporum semen, ova, vel nata progenies gravitate sua fundum petat?

Vel quia animalculis his perpetuus navium aut doliorum motus obstet, ut hæc non satis tuta credant, et ideo in fundo maris semper immota eligant corpora, quibus ovula sua confidant?

Vel quia pix et colophonia, quibus naves, dolia, et emissariorum januæ illuminuntur, corallinis, quæ illis increscunt, noxiam vel polypis ingratam qualitatem communicent? Hoc saltem semper obvenit, me numquam tot polypos invenisse in corallinis, quas a navibus, doliis aut emissariorum januis abraseram, quam in illis, quæ ostreis, mytulis et silicibus in fundo maris erant innatæ.

Hoc primum mihi argumentum est, corallinas a polypis non formatas esse; nam tunc plantæ juniores et minores æque suos haberent polypos, ac maximæ.

Secundum argumentum, quod polypi vel casu vel instinctu quodam sese corallinis affigant, sed veram plantæ partem non constituant, est, quod polypi non omnes majoris plantæ ramos æqualiter obsident; hic ramus vel hujus rami tantum pars polypis obsessa erit quam plurimis, altera nullis. Corallinam habeo, [148]cujus truncum plurimi inhabitant polypi, dum nullos in ramulis poteram detegere, licet armato oculo. Et sic algæ[149] vel quercui sic dictæ marinæ sæpius corallinæ increscunt, in quibus nunquam polypos inveni. Hoc fieri non deberet, si corallinæ polyporum essent opus. Omnes corallinæ semper suos deberent habere, et ramis suis æqualiter et proportionaliter insidentes polypos; et nunquam sine his essent reperiundæ, ut tamen sæpius sit. Cel. Jussieu[150] quasi mirabundus dicit, se semel alcyonium et spongiam ramosam sine polypis invenisse, licet recenter a rupe essent abstractæ.

Tertium argumentum erit, quod fere semper una eademque[151] corallinæ planta diversi generis alat polypis: in una eademque[152] corallinæ tubulariæ planta quinque diversas polyporum species inveni[153].

Liceat jam mihi rogare, quibusnam horum quinque hæc corallina ortum suum debeat? Certe non primæ aut secundæ, ut videtur, magnitudinis, nam hi summis tantum insident corallinæ extremitatibus, et microscopium clare ostendit locum, ubi corpus polypi minus pellucidum et superficiei rudioris glabræ huic corallinæ adhæret. Nec fabricavit corallinam tertia species, quæ extrema corporis parte, quasi caudâ, corallinæ est affixa: et minus adhuc quarta, nam clare videre est, horum cellulas corallinæ circumdatas, ut examen apum arboris ramum circumcludit: et si hæ polyporum cellulæ non nimis densæ sunt, ipsius corallinæ color translucet.

Si hæ quatuor polyporum species hanc corallinam non fabricaverint, non fecit certe quinta.[154]Mirabilissima et minima hæc animalcula ad genus polyporum certe pertinent, et omnibus fere corallinis, algis, aliisque plantis marinis incredibili sæpe insident copia. Jucundissimum est videre, quomodo se expandunt, et mox mira agilitate, capta prædâ, se subito contrahunt, quod bis vel ter in minuto horæ repetunt.

Æque jam, ut in una eademque corallinæ planta diversos invenis polypos, sic in diversis corallinæ speciebus videbis similes et eosdem polypos:[155] quod etiam illi obstat sententiæ corallinas polyporom esse opus aut fabricam. Polypi dum operantur, ut cætera animalia, instinctu innato operantur: ergo, una eademque polyporum species semper easdem fubricaret corallinas: sic semper similes et uniformes apes faciunt favos, vespæ nidos, araneæ tela. Hic vero contrarium eveniret; iidem polypi uno tempore hanc, alio tempore illam fabricarent corallinam: quod rationi contrarium est, et mihi quartum argumentum. Sed hoc verum est, quod eadem polyporum species non diversas corallinas, sed in diversis corallinis easdem et uniformes semper sibi construant cellulas.

Quinto, si corallinæ a polypis essent fabrefactæ, nunquam polypi et eorum cellulæ etiam vivis animalibus, aliisque corporibus, essent adfixæ. Polypos inveni in ostreorum[156] conchis, cancri[157] arachnoideæ pedibus, animali[158], quod emissariorum januis et navibus quietis sæpius adhæret et anus (aars-gat) vocatur, et aliis plurimis, sine minimo corallinæ vestigio. Et animalia illa, quæ piscatores nostri[159] klap-konten vocant, et majorum polyporum species esse videntur, nunquam teneris insident corallinis, sed semper hæc supra ostreorum conchas et lapides inveni, et quamvis illorum progressum ipse non viderim, tamen de loco in locum sese transmovisse, expertus sum.

Sexto: Hæ corallinæ non solum polypis, sed cochleis, buccinis[160] aliisque plurimis insectis marinis conveniunt, ut illis ova vel progeniem confidant. Hoc præcipue mensibus Februario et Martio videre est: accepi tunc diversas corallinas diversis cochleis et buccinis plenas, et sæpe inter hæc quosdam cancellos ova sua jamjam excludentes. Mater cochlea ovula sua supra vel juxta corallinas deposuit; pulli exclusi contra has ascenderunt, ne illis innixi fluctuum motu eluerentur, vel ut adversus hostes suos tuto se absconderent.

Quantum omnibus animalibus divina prospexerit prudentia, animus nunquam satis assequi quacunque industria potest. Deus, ut jam animadvertit Rex[161] Psalmista, plantavit arbores cedros Libani, ubi aviculæ nidificent, et abietes domicilia ciconiæ: Montes excelsissimos rupicaprarum, petras murium montanorum perfugium. Sic corallinæ domicilia et perfugium sunt polypis aliisque minoribus insectis marinis. Et præsertim hoc censeo, quia tempore hyemali, mensibus Decembri et Januario, corallinarum ramos plurimis vesiculis, operculo vel valvula tectis, obsessos inveni: quare has vesiculas habeo pro ovis ab aliis insectis his corallinis impositis.

Omnes, qui nunquam satis laudanda incomparabilis Reaumurii scripta legerunt, sciunt, quam miris et differentibus modis insecta quædam sua ova opponunt, vel in [162]gyrum, vel in [163]lineam spiralem, vel [164]singula ova a filis libere in aere pendentia, vel, ut hic fere casus est, per [165]paria lignosæ substantiæ ramorum imposita. Quam mira quam varia est etiam ipsorum [166]ovorum figura! Culicum[167] autem ova, quoad externam figuram, quam maxime his corallinæ vesiculis similia sunt.

Omnia vero insectorum ova inter se et cum his vesiculis in eo conveniunt, quod[168] operculum vel valvulum habent eo in loco, ubi eruca vel vermis exitum invenire debet; permittente quidem hac valvulâ exitum extrorsum, omnem vero introitum aëris vel aquæ prorsus negante. Sed præter hanc cum aliorum insectorum ovis convenientiam, ipsæ vesiculæ mihi vera ova videntur, quia recenter ex mare extractæ erant perspicuæ, in spiritu frumenti vero statim fiebant opacæ, albæ, cum puncto flavo[169]. Secundo, quia hyeme plures vesiculæ in corallinis reperiuntur, perpaucæ vero æstate; nam tum illorum pulli exclusi sunt, et corallinæ cochleis parvis, forsan ex his ovis progenitis, magis sunt obsessæ.

Nam hæ vesiculæ mihi ipsorum polyporum ova esse non videntur, licet sæpius [170]polypos in illis invenire contigit: et ideo crederem hos polypos in vesiculis repertos, quoniam licet adulti tamen vesiculis multo minores sint, post veri pulli exclusionem in vacua illa ova irrepsisse; cum jam antea observavimus cancellos in vacua irrepere buccina, et ipsos polypos vacuis corallinæ tubulariæ summitatibus sese adfigere. Sed quam maxime has vesiculas non polyporum, sed aliorum animalculorum ova esse censeo, quia perspicacissimus Reaumurius initio hyemis in oris Galliæ provinciæ Pictaviensis (Poitou) ova cochlearum marinarum invenerit, quæ quamvis his vesiculis paulum majora, erant tamen simillima[171]. Licet corallinæ speciosam habeant verisimilitudinem, ut quasi animalium opus appareant, aliæ tamen sunt plantæ marinæ, præsertim alcyonium digitatem molle, quas adhuc magis a polypis fabrefactas diceres; sed si accuratione indagine observantur, pro veris plantis erunt agnoscendæ, ut in posterum, quando profusius agam de plantis marinis, demonstrare spero. Alia vero alcyonia, ut vesicaria marina Bauhini, &c. vera animalium opera, namque eorum sunt ovaria. Plantæ marinæ unicæ non sunt, quæ pro insectorum opere sunt habitæ. Liceat mihi locum adferre ex notis, quas Nobilissimus Lyonnet Theologiæ insectorum Doctiss. el Rev. Lessers subjunxit: “Credendum non est, ut quidam faciunt, si stagnantes aquas viridi et fibrosâ membrana tectas videas, hanc insectorum texturam esse. Est algæ species, quæ in his stagnis crescit, et insectis est pro alimento.”[172]

De Polypis Corallinis insidentibus.

Completam historiæ et oeconomiæ polyporum in corallinis repertorum descriptionem dare nondum suscipio, sed paucis enarrabo, quæ de illis observare mihi licuit.

Auctores, qui aquæ dulcis polypos examinarunt, quatuor eorum species enumerant: sed in aqua marina major differentium specierum numerus est; plus quam viginti diversos vidi polypos, quos ut plurimum in laudatis figuris etiam delineavit accuratissimus Ellis, et profecto adhuc plures sunt. Sed hic monendum, quod cum aquæ dulcis polypi nudo oculo facile queant conspici, plerique marini non nisi lente aut microscopio possint examinari: et aqua marina, in qua polypi vivunt, bis, vel ad minimum semel, nucthemeri spatio, debet renovari, aut polypi moriantur.

Ad exemplum Di. Schaffer in duas species primo polypos distinguam; in polypos, qui cellulas sibi construant, et in polypos, qui corporis extremitate corallinis aliisque corporibus extus sese affigant, vel in cavitates naturales alcyoniorum, coralliorum, &c. (de quibus in posterum) irrepant, ut cancelli in vacua buccina. Polypi, qui in cellulis habitant, cæteris plerumque sunt minores: horum cellulæ corallinæ[173] truncum vel ramos circumdant, a quibus prudenti manu sine corallinæ læsione satis facile possunt abradi: et si hæ cellulæ non nimia sint copia, et corallina contra solis splendorem inspiciatur, præsertim si color vivide ruber, aureus aut subniger est, facile per ipsas cellulas translucet.

Polyporum, qui sine cellulis in corporum quorundam cavitatibus habitant, aut extrinsecus illis affixi sunt, plurimæ sunt species. Apertis[174] corallinæ tubulariæ ramis (nam in tali planta semper adsunt rami vel tubi naturaliter[175] clausi, id est, integri, in quibus nunquam polypus insidet) majorum polyporum species sæpius supra sedet; quos a colore rubente polypos vocabo coccineos, et præ cæteris observavi. In detritis et apertis, ut modo dixi, corallinæ tubulariæ ramulis, inserta sua cauda vel corporis parte posteriore, polypus habitat, et ex hoc ramo facile et sæpe levi quassatione delabitur, præsertim si ille jam per aliquot dies servatus debilis, æger, aut mortuus sit[176].

Si vegetum talem polypum, corallinæ insidentem, vehementius amplificante microscopio intueris, facile differentiam vides inter scabram et quasi granulatam polypi cutem, et lævissimam corallinæ corticem.

Hic polypus coccineus duplici brachiorum genere est munitus, quod in aliis minoribus non vidi; et hæc coloris sunt subalbidi. [177]Inferiora et longiora octodecim vel viginti sunt, nam numerus sæpe variat, et expansa patinam formant, in cujus medio[178] ipsum polypi corpus coccineum est. Hoc corpus in duas partes dividi potest. Inferiori placentam referenti perpendiculariter alia pyriformis est infixa, quæ duodecim[179] vel quatuordecim habet brachia, prioribus tenuiora et breviora.

Hanc partem pyriformem polypus valde [180]extendere potest, præsertim si prædam captans expansa claudit[181] brachia; et rursus ita contrahere, ut quasi [182]globulus inferiori et depressæ parti adhæreat. In extremo hujus partis [183]os polypi esse videtur: sed ob partium exilitatem non omnia satis distincta possunt videri, ut in majoribus aquæ dulcis polypis; sed ex similitudine partium hæc tuto licet concludere.

Si longiora brachia fortiori microscopio attente contemplaris, cutem eorum valde asperam vides, ut est piscium (quos Haijen vocant) vel ut superficies corii granulati (chagrein-leer) forsitan ut minora animalcula, quæ polyporum esca sunt, eo melius, ne elabantur, retinere possint. Sed inter hujus speciei polypos vidi umum cæteris[184] majorem, ex cujus corpore, illo loco ubi pars superior inferiori et depressæ inhæret, sex vel octo enascebantur[185] ramuli, in quorum extremitatibus erant duo vel tres parvi globuli, punctum coccineum in medio habentes. Huic polypo bis in die novam dedi aquam, quam maxime de ejus vita sollicitus, ea spe, ut hi globuli in juniores excrescerent polypos, sed quamvis per mensem sic vivum servaverim, nihil mutatum vidi, nisi quod globuli paululum evaserint majores.

Quæ deinceps de polyporum generatione observavi, non ita mihi satisfaciunt, ut illa pro certis et comprobatis habeam: si vero hac æstate meliora adiscam, Regiæ Societati indicabo.

De aliis Insectis Marinis.

Si noctu aqua maris, quæ littora nostra alluit, lapide injecto vel baculo movetur, innumeras videre est scintillas igneas, quæ nihil aliud sunt, quam minima animalcula lucentia, non nisi fortiore microscopio visibilia.

Ut hæc animalcula idoneâ colligas copiâ, sufficientem aquæ quantitatem, in qua has scintillas observasti, per chartam emporeticam filtrare facias, donec semiuncia aut minus aquæ supra chartam restat: hujus guttula, vitro concavo, penicilli vel pennæ ope, imposita, fortiore microscopio examinetur, et celerimo motu illa natare videbis. Tres diversas horum observavi species, quas ad vivum delineatas exhibet tabulæ [X.] fig. I.

Sed mare plura alit insecta, quibus hæc lucendi facultas inest, et quorum in corallinis repertorum quædam delineata sunt [tab X.] fig. 1, 2, 4, 5. sed quoniam plures [186]auctores de his scripserunt, non commemorabo.

Si corallinæ recenter ex mare extractæ major planta, orbi porcellano concavo, et cujus fundus est profundi coloris cærulei, cum sufficiente quantitate aquæ marinæ pellucidissimæ et filtratæ, at ante jam monui, imponatur, et ejus ramuli prudenter penna expandentur, et lente oculari inspiciantur, silvam saepius videre est, in qua plurima pascuntor animalia, præter diversi generis polypes ramis infixos et brachia extendentes: alia plura sunt, præsertim in infima parte, si corallinæ supra ostrea creverint, quæ huc et illuc cursitant, et forsitan sæpius hianti ostreo alimento inserviunt. Sic vigesimo tertio Octobris 1756 ostreum accepi, cui magna [187]corallinæ planta erat innata, in qua, præter tres diversas polyporum species, sex differentia reperiebam insecta. [188]Primum vermis erat, cujus caput sex majoribus et duobus minoribus cornubus erat instructum. [189]Alteram valde parvum araneam longipedem (Gallis le Faucheur) referebat, admodum lente se movens. Tertium vermis erat, similis figuræ 3, sed in designando deperdebatur. [190]Quartum, quintum et sextum non nisi fortiore microscopio distincte erant visibilia. Horum quod littera c nocatur, mirandæ erat structuræ.

Diversa sic ostrea et corallinas explorans, plura talia admiranda insecta vidi, quorum delineationem sistunt tabulae [X.] figuræ 2, 3, 4, 5, 7. Decimo sexto ejusdem mensis Octobris, plures mihi sed valde parvæ apportabantur corallinæ, quæ a dolio coniformi erant abrasæ: in his licet sæpe et attente exploratis nullos detegere poteram polypos, sed duo alia mirabilissima insecta.

Philos. Trans. Vol. L. Tab. VII. p. 275.

I. Rhosiud ad vivum pinxit.

J. Mynde sc.

Horum, quæ secunda figura tabulæ decimæ littera A exhibet, erant millia, celerrimo motu vel repentia vel natantia: sex suis pedibus postremis ramulum arripiebant, ut erucarum, quas geometras appellant, mos est, et mirum in modum prone et supine se flectentes, de ramo in ramum saliebant quasi agilissimi. Inter hæc erant pauca cæteris majora, quæ [191]naturali et [192]aucta magnitudine delineare curavi. [193]Alterum animal non minos mirum erat; sed horum omnium cognitio multo melius delineationis inspectu, quam ex valde prolixa descriptione peti potest.

Sed si omnia insecta marina, quæ in diversis corallinis reperi, delineare vellem, infinitum opus susciperem; nam eorum numerus et diversitas captum nostrum superant.

Hæc ergo, ut spero, sufficient ad demonstrandum corallinas non polyporum opus aut fabricam esse, sed his et plurimis aliis insectis marinis domicilio et perfugio aut alimento inservire.

Dabam ZirizϾ in Zelandia,
17 Martii 1757.