From hence I might proceed to the commodious Form of the Ribs[], the curious Mechanism of the Intercostal-Muscles[k], the Diaphragm, and all the other Muscles[l] ministring both to the ordinary, and extraordinary Offices of Respiration. But passing them by, I shall stop at one prodigious Work of Nature, and manifest Contrivance of the Almighty Creator, which although taken notice of by others[m], yet cannot be easily passed by in the Subject I am upon; and that is the Circulation of the Blood in the Fœtus in the Womb, so different from the Method thereof after it is Born. In the Womb, whilst it is as one Body with the Mother, and there is no Occasion, nor Place for Respiration, there are two Passages[n] on purpose for the Transmission of the Blood without passing it through the Lungs. But as soon as the Fœtus is Born, and become thereby a perfectly distinct Being, and breathes for it self, then these two Passages are shut up: one nearly obliterated, the other becomes only a Ligament, except in some Creatures that are Amphibious, or are forced to lie long under Water, in whom these Passages probably remain open[o].
And now what Action of any rational Creature, what is there in a Man’s Life, that doth more plainly shew Design, Reason, and Contrivance, than this very Act of Nature doth the Contrivance and Design of the great GOD of Nature? What is Thought and Contrivance, if this be not? Namely, That there should be a temporary Part in the Body, made just for the present Exigence; to continue whilst there is occasion for it, and to cease when there is none; in some Creatures to remain always, by Reason of their amphibious Way of Living, and in Land-animals (purely such) to cease?
Another excellent Contrivance, a-kin to the last, is, for the Preservation of such Creatures whose occasions frequently necessitate them to live without, or with but little Respiration: Fishes might be named here, whose Habitation is always in the Waters; but these belong to an Element which I cannot at present engage in. But there are many Animals of our own Element, or partly so, whose Organs of Respiration, whose Blood, whose Heart, and other Instruments of Life, are admirably accommodated to their Method of Living: Thus many amphibious Creatures[p], who live in Water as well as Air; many quadrupeds, Birds, Insects, and other Animals, who can live some Hours, Days, yea, whole Winters, with little or no Respiration, in a Torpitude, or sort of Sleep, or middle State between Life and Death: The Provision made for these peculiar Occasions of Life, in the Fabrick of the Lungs, the Heart, and other Parts of such Creatures[q], is manifestly the Work of him, who as St. Paul saith[r], giveth to all Breath, and Life, and all Things.
FOOTNOTES:
[a] The Uses assign’d to Respiration by all the Anatomists before Malpighi’s Discoveries of the Structure of the Lungs, are so various, and many of them so improbable, that it would be frivolous to recount them. But the more eminent modern Anatomists assign these Uses. Willis thus sums up his Opinion, Præcipua Pulmonum functio, & usus sunt, sanguinem & aerem per totas partium compages, intimosque recessus, atq; ductus quosque minutissimos traducere, & ubique invicem committere; in cum nempe finem, ut sanguis venosus à circuitu redux, & chymo recenti dilutus,——tum perfectiùs misceatur & velut subigatur, tum potissimùm ut secundùm omnes suas partes ab aëre nitroso de novo accendatur. Pharmaceut. p. 2. S. 1. c. 2. §. 2. Mayow saith rightly, that one grand Use of Expiration is, Ut cum aëre expulso, etiam vapores è sanguine exhalantes, simul exsufflentur. And as for Inspiration, that it coveyeth a nitro-aerial ferment to the Blood, to which the Animal-Spirits are owing, and all Muscular-Motion. Mayow de Respir. p. 22. &c. meâ Edit.
Somewhat of the Opinion of these two last cited, if I mistake not (it being long since I read their Tracts, and have them not now at hand,) were Ent, Sylvius, Swammerdam, Diemerbroek, and my Friend Mr. Ray in an unpublished Tract of his, and in his Letters now in my Hands.
But our Dr. Thurston, for good Reasons, rejects these from being principal Uses of Respiration, and thinks, with great Reason, the principal Uses to be to move, or pass the Blood from the right to the left Ventricle of the Heart. Upon which account Persons hanged, drowned, or strangled by Catarrhs, so suddenly die, namely, because the Circulation of their Blood is stopped. For the same Reason also it is, that Animals die so soon in the Air-Pump. Among other Proofs he instanceth in an Experiment of Dr. Croon, Profess. Gresh. which he made before our R. S. by strangling a Pullet, so that not the least Sign of Life appear’d; but by blowing Wind into the Lungs through the Trachea, and so setting the Lungs a playing, he brought the Bird to Life again. Another Experiment was once tried by Dr. Walter Needham, before Mr. Boyl, and others at Oxford, by hanging a Dog, so that the Heart ceased moving. But hastily opening the Dog, and blowing Wind into the Ductus Pecquetianus, he put the Blood in Motion, and by that means the Heart, and so recovered the Dog to Life again. V. Thurston de Respir. Us. p. 60, and 63. meâ Edit.
Such an Experiment as Dr. Croon’s my Friend, the late justly renowned Dr. Hook shewed also our R. S. He cut away the Ribs, Diaphragm, and Pericardium, of a Dog; also the top of the Wind-Pipe, that he might tie it on to the Nose of a Pair of Bellows; and by blowing into the Lungs, he restored the Dog to Life; and then ceasing blowing, the Dog would soon fall into dying Fits; but by blowing again, he recovered; and so alternately would die, and recover, for a considerable Time, as long, and often as they pleased. Philos. Trans. Nᵒ. 28.
For the farther Confirmation of Dr. Thurston’s Opinion, the ingenious Dr. Musgrave cut off, and close stopped up the Wind-Pipe of a Dog with a Cork, and then threw open the Thorax; where he found the Blood stagnating in the Lungs, the Arteria Pulmonaris the right Ventricle and Auricle of the Heart, and the two great Trunks of the Cava, distended with Blood to an immense Degree; but at the same Time, the Vena Pulmonaris, the left Ventricle and Auricle of the Heart in a manner empty, hardly a spoonful of Blood therein. Philos. Trans. Nᵒ. 240. Or both the Experiments may be together met with in Lowth. Abridg. Vol. 3. p. 66, 67.
This Opinion of our learned Thurston, the late learned Etmullerus espoused, who being particular in reckoning up the Uses of Respiration, I shall therefore the more largely cite him. Respiration, saith he, serves, 1. Ad Olfactum. 2. Ad Screatum & Sputationem. 3. Ad Oscitationem, Tussim, Sternutationem, Emunctionemque. 4. Ad liquidorum Sorbitionem, Suctionemve. 5. Ad Loquelam, Cantum, Clamorem, Risum, Fletum, Flatum, &c. 6. Ad facum Alvi, Urinæ, Fœtûs Molæve, necnon Secundinarum expulsionem. 7. Ad promovendi Ventriculi, Intestinorum, Lacteorumque vasorum, &c. contenta. 8. Ad halitus aqueos Sanguinis è pulmonibus, aëris ope, exportandos. 9. Ad Diapnoën. 10. Ad exactiorem Chyli, Lymphaque, necnon Sanguinis——miscelam. 11. Ad conciliandum sanguini——coccineam rubedinem, &c. 12. Nec merosè negabimus, aërem——pulmones, & sanguinem illos transcurrentem, minùs calida reddere, &c. 13. Quod denique aër sanguini singulis Respirationibus aliquantillâ sui parte, admixtus, paucissimas quasdam in spiritum animalium elaboratione particulas simul contribuat. All these Uses, although of great Consequence, yet he thinks rather conduce to the Well-Being, than the Being of the Animal; because without any of them, the Animal would not so speedily die, as it doth by Strangling, or in the Air-Pump. He therefore assigns a 14ᵗʰ, and the principal Use of Respiration to be, For the passing of the Blood through the Lungs, that is thrown into them by the Heart. Etmull. Dissert. 2. c. 10. §. 1. & 16.