1^8 On the different Gafes. 



At the fame period, F. Slave and T. Willis afcribed * the 

 dark red colour of the blood to the air; and J. Mayowt, 

 another Englifliman, with whom another Oxford p«iyfician, 

 Henry Mund %, and alfo Willis §, L. M. Barbieri, and 

 J. B. Giovanni ||, concurred, made the whole ufe of breath- 

 ing toconfift in this — that the lungs of animals inhale from 

 the atmofphere nitrous particles, which are difi'uled over the 

 animal fpirits and communicate warmth to the blood. 

 J. N. Pechlin^, alfo, attributes the faculty of fome divers 

 being able to remain longer under water to a greater quan- 

 tity of nitre. From all this it appears that the phyficians of 

 that period had a kind of idea of vital air, and its influence 

 on the animal oeconomy. 



Stephen Hales, who made further progrefs by his nume- 

 rous experiments in difcovering the fccrets of nature, placed 

 beyond all doubt, by a long feries of experiments, the clafti- 

 city of thefe fluids as they are expelled from bodies by heat, 

 fermentation, corruption, and efl'ervefccnce, a power which 

 was before obfervcd by Newton**, and at the fame time 

 fliowed feveral and ingenious methods ft how they could be 

 obtained, prcrer\'ed, meafured, weighed, and even handFed. 

 He remarked the inflammability of thofc which the inflam- 

 riable bodies of every kingdom of nature yield by cxpofure 

 to a ftrong heat, the properties of others which arifc from 

 eflervcfcing mixtures, and which fuddenly extinguilh flame. 

 He obferved likewife, exceedingly well, the great diflerence 

 of the nitrous gas which he obtained when he poured upon 

 antimony aqzui rigia, or fpirit of nitre ; or the latter diluted 

 with water [aquafortis] upon iron filings or quickfilver, and 

 its property of forming red clouds with common air as foon 

 as it comes in contact with it ; and, bv repeated experiments, 

 that it abforbed a great portion of air ; and alfo, that the 

 oftener the experiment was repeated, the gas alwavs abforbed 

 the lefs air; that feveral of thefe gafes were abforbed by 

 water; how much the bell air is corrupted by the breath- 

 ing of even the foundeft men, fo that at lall it is totally 



* Phiiofophical Tranfa£lions for i6Si, no. 104. Ibid. p. 92 — 94. 



f Traftatus quinque Medicophyfici ; Oxon. iSgcy. b'vo, no. i, 



+ E(5;^firo>9;"« ; Oxnn. 16S0. Svo. 



§ Phiiolcpli. Traiiliii'.t. ut fupra. 



li Spiritus Nitro Acrii Opcrationes in Microcrifmum ; P.onon. 16S1, 

 i2n o. Diflertation, fur la F'-rmentation fur le Nitre et fur FAir; Tou- 

 loufc if>Si;. izmo. 



«f[ De Aeris tt Alimcnti Defeftu ; Kilon.i676, Evo. 



•♦ Optics; London 1701. 4to. 



•{■f Statical Effays; London, 8vp, tjiird edit. 17S3. vol. i. c. 6. and 

 vol. ii. p. 3 '5- 3''". 



unfit 



