1 CHA P. II. Of Refpiration. F all the Acts of Animal Life, this is one of the chief, and moft neceffary. For whatfoever hath Animal Life, hath alfo the Faculty of Refpiration, or fomewhat equivalent thereto (1). In deed (1) The Ufes affign'd to Refpiration by all the Anatomifts before Malpighi's Discoveries of the Structure of the Lungs, are fo various, and many of them fo improbable, that it would be fri volous to recount them. But the more eminent modern Anatomifts affign these Ufes. Willis thus fums up his Opinion, Preci pua Pulmonum functio, & usus sunt, fanguinem & aerem per totas partium compages, intimofque receffus, atq; dullus quofque minutiffi mos traducere, & ubique invicem committere; in eum nempe fr nem, ut fanguis venofus à circuitu redux, chymo recenti dilutus,tum perfectius mifceatur & velut fubigatur, tum potiffimum ut fecundum omnes fuas partes ab aere nitrofo de novo accendatur. Pharmaceut. P. 2. S. I. c. 2. §. 2. Mayo faith rightly, that one grand Ufe of Expiration is, Ut cum aere expulfo, etiam vapores è fanguine exhalantes, fimul exfufflentur. And as for Infpiration, that it conveyeth a nitro-aerial ferment to the Blood, to which the Animal Spirits are owing, and all Muscular-Motion. Mayow de Refpir. p. 22. c. mea Edit. Somewhat of the Opinion of these two laft cited, if I mistake noc (it being long fince I read their Trafts, 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 Ray in an unpublished Tract of his, and in his Letters now in my hands.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 Ufes of Respiration, and thinks, with great reason, the principal Ufes to be to move, or pafs the Blood from the right to the left Ventricle of the Heart. Upon which account Perfons hanged, drowned, or ftrangled by Catarrhs, fo fuddenly die, namely, because the Circulation of their Blood is ftopped. For the fame reason alfo it is, that Animals die fo foon in the AirPump. Among other Proofs he inftanceth in an Experiment of Dr. Croon, (Profeff. Gresh.) which he made before our R. S. by ftrangling a Pullet, fo that not the leaft Sign of Life appear'd; but deed fo congenial is this with Life, that Breath and Life are in Scripture Phrafe and Common Speech taken but by blowing Wind into the Lungs through the Trachea, and fo feuing the Lungs a playing, he brought the Bird to Life again. Another Experiment was one tried by Dr. Walter Needham before Mr. Boyl, and others at Oxford, by hanging a Dog, fo that the Heart ceafed moving. But baftily opening the Dog, and blowing Wind into the Duftus Pecquetianas, he put the Blood in Motion, and by that means the Heart, and fo recovered the Dog to Life again. Thurston de Respir. Uf. p. 60, and 63 med Edit. Such an Experiment as Dr. Croon's my Friend, the late juftly renowned Dr. Hook fhewed alfo our R. S. He cut away the Ribs, Diaphragm, and Pericardium of a Dog, alfo the top of the Wind-Pipe, that he might tie it on to the Nofe of a pair of Bellows; and by blowing into the Lungs, he restored the Dog to Life, and then ceafing blowing, the Dog would foon fall into dying Fits; but by blowing again, he recovered; and fo alternately would dies and recover, for a confiderable time, as long, and often as they pleased. Philof. Tranf. Nr. 28. - For the farther. Confirmation of Dr. Thurfion's Opinion, the ingenious Dr. Musgrave cut off, and clofe ftopped up the Windpipe of a Dog with a Cork, and then threw open the Thorax ; where he found the Blood ftagnating in the Lungs, the Arteria Pulmonaris the right Ventricle and Auricle of the Heart, and the two great. Trunks of the Cava, diftended with Blood to an immense degree; but at the fame time, the Pena Pulmonaris, the left Ventricle and Auricle of the Heart in a manner empty, hardly afpoonful of Blood therein. Philof. Tranf. Nr. 240. Or both the Experiments may be together met with in Lowth. Abridg. Vol. 3 p. 66, 67. •3• This Opinion of our learned Thurston, the late learned Etmuller efpoufed, who being particular in reckoning up the Ufes of Refpiration, I fhall therefore the more largely cite him. Re fpiration, faith he, ferves, E. Ad Olfactum. 2. Ad Screatum Sputationem. 3. Ad Ofcitationem, Tuffim, Sternutationem, EmunEtionemque. 4. Ad liquidorum Sorbitionem, Suctionemve. 5. Ad Loquelam, Cantum, Clamorem, Rifum, Fletum, Flatum, &c. 6. Ad fecum Alvi, Urine, Eœtus, Molave, necon Secundinarum, expulfionem. 7. Ad promovendi Ventriculi, Inte@inorum, Lacteorumque vaforum, &c. contenta. 8. Ad halitus aqueos Sanguinis è pulmonibus, aeris ope, exportandos. 9. Ad Diapnoen. 10. Ad exactiorem Chyli, Lymphaque, necnon Sanguinis- -miscelam. 11. Ad L 2 conci conciliandum fanguini-coccineam rubedinem, &c. 12. Nec morosè negabimus, aerem pulmones, & fanguinem illos tranfcurrentem, minus calida reddere, &c. 13. Quod denique aer fanguini fingulis Refpirationibus aliquantillâ fui parte, admixtus, pauciffimas quafdam in Spirituum animalium elaboratione particulas fimul contribuat. All these Ufes although of great Confequence, yet he thinks rather conduce to the Well-Being, than the Being of the Animal because without any one of them, the Animal would not fo fpeedily die, as it doth by Strangling, or in the Air-Pump. He therefore afligns a 14th, and the principal Ufe of Respiration to be, For the paffing of the Blood through the Lungs, that is thrown into them by the Heart. Etmull. Differt. 2. c. 1o. § 1, & 16. ; But the late Dr. Drake, with great Ingenuity and Address, (like a Perfon fo confiderable for his Years, as he was in his Time,) not only establish'd this Notion of Respiration, but also carries it farther, making it the true Caufe of the Diastole of the Heart; which neither Borelli, Lower, or Cowper, much less any before thofe great Men, have well accounted for. That the Heart is a Mufcle, is made evident beyond all doubt by Dr. Lower. And that the Motion of all Muscles confifts in Constriction, is not to be doubted also. By which means the Syftole is eafily accounted for. But forafmuch as the Heart hath no Antagonist-Muscle, the Diastole hath puzzled the greatest Wits. But Dr. Drake with great Judgment, and much Pobability of Reason, maketh the Weight of the Incumbent Atmosphere to be the true Antagonist to all the Muscles which ferve both for ordinary Inspiration and the Conftriction of the Heart. The particulars of his Opinion may be seen in his Anatomy, L. 2. c. 7. And in Philof. Trans. 281. And I remember when I was at the Univerfity, my most inge. nious and learned Tutor Dr. Wills, when he read. Anatomy to us, was of Opinion, that the Lungs were blown up by the Weight of the incumbent Air, and reprefented the manner of Refpiration in this manner, viz. He put a Bladder into a pair of Bellows, turning back the Neck of the Bladder, and tying it faft, so that no Air might enter in between the Bladder and Bellows. This being done, when the Bellows were opened, the Bladder would be blown up, by the Weight of the incumbent Air; and when thut, the Air would be thereby preffed forcibly out of the Bladder, fo as to blow the Fire. This Experiment I take notice of here, because (befides the Illuftration it gives to Refpiration) that great Genius feems to have had a truer No Concomitants of one another. Mofes (2) expreffeth And here I might launch out into an ample De scription of all the Parts miniftering to this neceffary Act, and fhew the curious Contrivance and artificial Structure of them. But a tranfient View fhall fuffice. I might begin with the outward Guards, the Nofe and Mouth; but thefe have been already touched upon. But the exquifite Mechanifm of the Larynx, its Variety of Muscles, its Cartilages, all fo exquifitely made for the purpose of Refpiration, and forming the Voice (3), are very ad tion of this Phenomenon than was very common then, viz. about the Year 1677 or 78; as alfo, because I have in fome Authors met with the fame Experiment, without mention of Dr. Wills, whose I take it to have been. Another ufe, of great confideration, the already commended Dr. Cheyne affigns, namely, to form the elaftick Globules of which the Blood principally confifts, without which there would be a general Obstruction in all the capillary Arteries. Cheyne's Phil. Prin. of Nat. Rel. or Harris's Lex. Tech. in Lungs. (2) Gen. 2. 7. 6. 17, & 7. 15. (3) Because it would be endless to specify the curious Mechanism of all the Parts, concurring to the Formation of the Voice, I fhall therefore for a Sample note only two things. 1. There are thirteen Muscles provided for the Motion of the five Cartilages of the Larynx. Gibs. Anat. 4. 2. c. 14. A Sign of the careful and elaborate Provision that is made for the Voice. It is a prodigious Faculty of the Glottis in contracting and dilating it felf with fuch Exquifitenefs, as to form all Notes. For (as the ingenious Dr. Keil faith) fuppofing the greatest Distance 2. admirable: And no lefs fo is the Tongue (4), which minifters to that, and many other Ufes too. Next, the Fabrick of the (5) Trachea deferves efpecial Remark. Its Valve, the Epiglottis on the top, of the two Sides of the Glottis to be one tenth Part of an Inch in founding 12 Notes, (to which the Voice easily reaches,) this Line must be divided into 12 Parts, each of which gives the Aperture requifite for fuch a Note, with a certain Strength. But if we confider the Sub-divifion of Notes into which the Voice can run, the Motion of the Sides of the Glottis is still vaftly nicer. For if two Chords founding exactly Unifons, one be shortened th Part of its Length, a juft Ear will perceive the Difagreement, and a good Voice will found the Difference, which is th Part of a Note. But fuppofe the Voice can divide a Note into 100 Parts, it follows that the different Apertures of the Glottis actually divide the tenth Part of an Inch into 1200 Parts, the effect of each of which produces a fenfible Alteration upon a good Ear. But because each fide of the Glottis moves just equally, therefore the Divifions are ju? double, or the Sides of the Glottis, by their Motion, do actually divide one tenth Part of an Inch into 2400 Parts. Keil's Anat. c. 3. Sect. 7. (4) Among the Inftruments of Speech, the Tongue is a neceffary one; and fo neceffary, that it is generally thought no Speech can be without it. But in the third Tome of the Ephem. Germ. is publifhed, Jac. Rolandi Agloffoftomographia, five Defcriptio 0ris fine Lingua, quod perfectè loquitur, & reliquas fuas functiones naturalitèr exercet. The Perfon defcribed is one Pet. Durand, a French Boy of eight or nine Years Old, who at five or fix, loft his Tongue by a Gangrene, occafioned by the Small-Pox. Notwithstanding which, he could (as the Title faith) fpeak perfectly, as alfo Tafte, Spit, Swallow, and Chew his Food; but this latter he could do only on that fide he put it into, not being able to turn it to the other fide his Mouth. In the fame Tract, Chap. 6. is this Obfervation of Ventrilo. quous Perfons, Memini me à quodam fat celebri Anatomico audivisse, dum de duplicaturâ Mediastini ageret, fi Membrana ifta duplex naturalitèr unita in duas partes dividatur, loquelam quafi ex pectore procedere, ut circumftantes credant Damoniacum hunc, aut Sternomythum. (5) The Variation of the Wind-pipe is obfervable in every Creature, according as it is necessary for that of the Voice. In an Urchin, which hath a very small Voice, 'tis hardly more than Mem branous. |