MISCELLANY.
The Transparency of the Sea. —At a late meeting of the French Academy of Science, M. Cialdi and Father Secchi sent the result of some observations they have made "On the Transparency of the Sea." The experiments were made at the end of April, on board a vessel, near Civita Vecchia, from six to twelve miles from land, and at depths varying from 90 to 300 metres, the sea being perfectly clear and tranquil. Discs of different diameters and colors attached to wires being plunged horizontally under water, showed that the maximum depth at which the largest (a white disc 3-1/4 metres in diameter) could be seen was 42-1/2 metres, the sun being elevated 60-1/4° above the horizon. With a vertical sun the depth of visibility shall be 45 metres. The color of the disc appeared at first a light green, then a clear blue, which became darker as it was lowered, until it could no longer be distinguished from the surrounding medium. Discs of a yellow or sandy color disappeared at less than half the depth of the white discs—that is to say, between 17 and 24 metres. The height of the sun and the clearness of the sky greatly influence the depth at which objects may be seen. Viewing the light reflected from a submerged white disc through a spectroscope, the red and yellow colors were found to be rapidly absorbed. As it was sunk deeper in the sea a portion of the green became absorbed, the other colors remaining unaltered. The authors remark that this luminous absorption of the more refrangible rays is what would be expected from the calorific opacity and the actinic transparency of water. From the foregoing results, they doubt whether the bottom of the sea has ever been seen at a depth of 100 metres, as it is more probable that the mud and sand brought up by waves has been mistaken for such: the fact that the bottom of the sea is a worse reflector than the white disc, strengthens this supposition.
Irish Limestone Caverns.—At a late meeting of the Cork Cuvierian Society, Professor Harkness, so well known for his investigations of Scottish rocks, announced the discovery of the bones of mammals in a limestone quarry at Middleton, County Cork. The rock consists of the ordinary limestone of the district, in one part much fissured, and under this fissured portion there is a mass of brown clay, the thickness of which cannot be determined, as its base is not seen. This reddish-brown clay under the limestone is the deposit which furnishes the fossil bones, and which, doubtless, fills the space which was once a natural grotto. Beside the bones, which are in a fragmentary condition, there are also present teeth and antlers. The latter are much broken, and do not afford sufficient character to enable the species to be accurately determined. They seem, however, to belong to two forms, one of which had the beam and branches smooth and sub-compressed, features which indicate the antlers of the reindeer; and the other with the horns rounded and rough, a form of surface which marks the antlers of the common stag. Of these antlers two portions which appear to belong to the reindeer have been cut while in the fresh state; and the faces of the cuts being almost smooth, this cutting appears to have been effected by a fine regular-edged instrument rather than, by a serrated tool. The leg bones which appear in this clay have all been broken, for the most part longitudinally, except the carpal and tarsal, and other small bones of the extremities. This longitudinal fracturing of the long bones of the leg is not known to occur in any mammalian remains which belong to a period previous to that where we have evidence of the existence of [{137}] the human race; and these broken bones afford evidence of the occurrence of man, who, for the purpose of obtaining the marrow, divided them in the direction most available for this object. Beside the evidence afforded by the cut antlers and longitudinally divided bones, there are other circumstances indicating the occurrence of man in connection with these remains; one of these is the presence of charred wood, which is equally disseminated through the clay with the bones and teeth. This charred wood is the remains of the ancient fires by means of which former human beings cooked their food.
Is there an Open Arctic Sea?—Sir Roderick Murchison, who answers this question in the affirmative, gives the following arguments in support of his opinion:—(1.) The fact has been well ascertained by Scoresby and others, that every portion of the floating pack-ice north of Spitzbergen is made up of frozen sea-water only, without a trace of terrestrial icebergs like those which float down Baffin's Bay, or those which, carrying blocks of stone and débris, float northward from the land around the South Pole. (2.) The northern shores of Siberia tell the same tale; for in their vast expanse the absence of icebergs, or erratic blocks, or anything which could have been derived from great or lofty masses of land, has been wen ascertained. (3.) As a geologist, Sir R. Murchison could point out that this absence of erratic blocks in northern Siberia has existed from that remote glacial period when much larger tracts of northern Europe were occupied by glaciers than at the present day. (4.) The traveller Middendorf found the extreme northern promontory of Siberia, Taimyr, clad with fir trees, while the immense tract of country to the south of it was destitute of trees, showing a milder climate at that point of Siberia nearest the pole.
Food as a Means of Preventing Disease,—It seems not at all improbable that, as has been shown by Liebig in the case of plants, most of those diseases which we at present attribute to the presence of some morbid substance in the blood, are produced in the first instance by the absence of some of the proper constituents of the blood. The blood when abnormally composed will allow vegetable and other growths to take place in it, thus producing painful symptoms; but if it contained its suitable components, it is most probable that it would be then enabled to resist the development of the materials we refer to. In the case of the potato disease, there can hardly be a doubt that the sap becomes deteriorated, owing to the absence of the proper proportion of potash, prior to the development of the oïdium which commits such ravages. The idea which we have given has not had many advocates in this country, and we are glad to find that Mr. Erasmus Wilson has in some measure lent his support to the theory. Although Mr. Wilson does not go as deeply into the question as we should wish, still he shows that food may well be employed not only in preventing but in curing disease. If, he says, it be admitted that food is the source of the elements of which the body is composed, what kind of body can be expected in the case of a deficient supply of food, whether that deficiency proceed from actual want, or from some perverse theory of refinement, founded on a false conception of the nature and objects of food, and ignorance of its direct convertibility into the flesh and blood of man? We think Mr. Wilson is too determined a supporter of flesh-eating tastes. If he had his way, he would convert man into a decidedly carnivorous animal, and we do not think that either experience or an appeal to the anatomy of the human masticatory and digestive organs would bear out his views.—Vide "On Food as a Means of Prevention of Disease."
Are the Flint Implements from the Drift Authentic?—A pamphlet has appeared from the pen of Mr. Nicholas Whitley, of the Royal Institution of Cornwall, in which it is attempted to be proved that the so-called flint implements are not the result of workmanship. The Popular Science Review gives the following abstract of Mr. Whitley's argument: (1.) The "implements" are all of flint. The tools employed by men of the recognized archaeological stone age are made of stones of various kinds, of which there are examples of serpentine, granular greenstone, indurated claystone, trap greenstone, claystone, quartz, syenite, chest, etc. Why, therefore, [{138}] should the only weapon in the drift deposit be manufactured from flint solely? (2.) The "implements" are all of one class—axes. Were they then a race of carpenters? Man is a cooking animal; and if ten thousand axes have been found, surely one seething-pot or drinking-cup ought to have turned up. He needs shelter, but no remnant of his clothing or hut has been found. Almost everywhere where there are chalk flints we find axes, and nothing but axes. (3.) There is a gradation in form from the very rough fracture of the flint to the perfect almond-shaped implement. Let the most enthusiastic believer in their authenticity examine carefully the one thousand implements in the Abbeville museum, and he would probably reject two-thirds as bearing no evidence of the work of man. But it would be impossible for him to say where nature ended and art began. (4.) Some of the implements are admirable illustrations of the form produced by the natural fracture of the egg-shaped flint nodule. (5.) It is supposed that these weapons were used for cutting down timber and scooping out canoes. But it should be remembered that the gravels in which they are found were formed during a severe Arctic climate, in which no tree but a stunted birch could have grown, certainly none large enough to form a canoe. (6.) Their number. The implements are found by thousands in small areas, and in numbers quite out of proportion to the thinly scattered population that must have (if at all) then existed.
The Sponge Fishery.—The main industry of the island of Crete is the sponge fishery which is pursued on its coasts. It is chiefly carried on by companionships of from twenty to thirty boats, for mutual support and protection. The mode of operation preparatory to a dive is very peculiar and interesting. The diver whose turn it is takes his seat on the deck of the vessel, at either the bow or stern, and placing by his side a large flat slab of marble, weighing about 25 lbs., to which is attached a rope of the proper length and thickness (1-1/2 inch), he then strips, and is left by his companions to prepare himself. This seems to consist in devoting a certain time to clearing the passages of his lungs by expectoration, and highly inflating them afterward; thus oxidizing his blood very highly by a repetition of deep inspirations. The operation lasts from five to ten minutes, or more, according to the depth; and during it the operator is never interfered with by his companions, and seldom speaks or is spoken to; he is simply watched by two of them, but at a little distance, and they never venture to urge him or distract him in any way during the process. When from some sensation, known only to himself, after these repeated long-drawn and heavy inspirations, he deems the fitting moment to have arrived, he seizes the slab of marble, and, after crossing himself and uttering a prayer, plunges with it like a returning dolphin into the sea, and rapidly descends. The stone is always held during the descent directly in front of the head, at arm's-length, and so as to offer as little resistance as possible; and, by varying its inclination, it acts likewise as a rudder, causing the descent to be more or less vertical, as desired by the diver. As soon as he reaches the bottom he places the stone under his arm to keep himself down, and then walks about upon the rock, or crawls under its ledges, stuffing the sponges into a netted bag with a hooped mouth, which is strung round his neck to receive them; but he holds firmly to the stone or rope all the while, as his safeguard for returning and for making the known signal at the time he desires it. The hauling up is thus effected: The assistant who has hold of the rope awaiting the signal, first reaches down with both hands as low as he can, and there grasping the rope, with a great bodily effort raises it up to nearly arm's-length over his head; the second assistant is then prepared to make his grasp as low down as he can reach, and does the same; and so the two alternately, and by a fathom or more at a time, and with great rapidity, bring the anxious diver to the surface. A heavy blow from his nostrils to expel the water and exhausted air indicates to his comrades that he is conscious and breathes, a word or two is then spoken by one of his companions to encourage him if he seems much distressed, as is often the case; and the hearing of the voice is said by them to be a great support at the moment of their greatest state of exhaustion. A few seconds' rest at the surface, and then the diver returns into the boat to recover, generally putting [{139}] on an under-garment or jacket, to assist the restoration of the animal heat he has lost, and to prevent the loss of more by the too rapid evaporation of the water from his body.—Travels in Crete.
The Sun's Spots.—Father Secchi writes from Rome, under date of Aug. 8, to the Reader as follows: I thank you for the interest you take in the observations of the sun. The last large spot has been very interesting for science, and I hope to be able to publish all the drawings we have made of it by projection. Meanwhile I send you two of them, photographed on a large scale. You will see in the printed article which I send you, that I have been able to see the prominences and depressions produced by the spot at the edge of the sun; not only myself but also M. Tacchini. I regret that the shortness of time does not allow me to copy the drawings made on that occasion, but I send a copy of them to Mr. De la Rue, and you will see them. As to the willow-leaves and rice-grains question, I think, as you say, we are all right and all wrong. I will state clearly what I see. On first placing the eye to the telescope, and in very good moments of definition, the surface of the sun appears certainly to me made up of many oblong bodies, which I think are the willow-leaves of Mr. Nasmyth; their orientation is in every direction, but they take a converging direction in the neighborhood of the spots, where they form the tongues, currents, and such like. But this view is, as I said, rather difficult to obtain, and many times I have looked for it quite without success. Is this a defect of vision, or caused by the sun's changements? If by willow-leaves other things than these are understood, I have not seen them. M. Airy seems to understand other things, and then I am quite at a loss. This, therefore, is a matter very problematic, and to be better studied. By projection on a large scale in some beautiful moments of definition, these oblong bodies on the general surface of the sun have been seen by my assistant also; but generally they are not visible, but the sun appears like clouds. As to the mobility of the solar surface, you can judge from the two photographs that I send you; they have been made only at an interval of twenty-four hours. I think we assisted at the outbreaking of the spot, and at its arrangement from a great confusion of movements into a regular transformation of an ordinary group of spots. The appearance which I have seen is quite like that which takes place when a great movement is excited in a stream of running water, which finally resolves itself into some vortices which take their course independently. The movement of these spots even alone is capable of demonstrating materially what Mr. Carrington has found with great labor—that there is in the sun a real drift of matter, since without this it would be impossible to explain how the spot has been increased in two days to a length twice as great as its breadth, this remaining almost constant. But more of this in a particular memoir.