528 , PHILOSOPHICAL TRANSACTIONS. [aNNO 1779. 



it in the same manner as when the experiment was tried on water. In all these 

 cases the air, after the animals had died in it, was still inflammable, nor did its 

 exploding properties seem to have been at all diminished. 



The inflammable air extracted from zinc, and that extracted from iron, is 

 fatal to animals even after it has been shaken in water for a minute's time, or 

 something longer. By shaking it a long time, it becomes in some measure 

 respirable ; but then it is decomposed in a great measure, and becomes of 

 another kind, though it still preserves the properties of being inflammable, but 

 in a smaller degree. Not only birds but also quadrupeds die in inflammable air, 

 though not so soon, and show some signs of being convulsed. 



It seems very strange, that Mr. Scheel could breathe inflammable air with 

 impunity, when animals obliged to breathe it were killed in a very short time. 

 Admitting his experiments to be true, there remains nothing to be said, but 

 that the inflammable air in which animals die does not occasion death because it 

 is conveyed to the lungs, but because it affects some other organs of the animal 

 body exposed to that air, and necessary to animal life. It is not impossible to 

 occasion death by affecting the very sensible nerves of the nose ; it being well 

 known, that various liquors, as very concentrated volatile alkali, &c. if they are 

 inspired through the nose, immediately affect the senses, and occasion death if 

 they continue to act on the pituitary membrane. In order therefore to try, 

 whether inflammable air killed only because it was inspired through the nose, I 

 stopi)ed very accurately the noses of various birds with soft wax, and in this 

 manner I introduced them into receivers full of inflammable air extracted from 

 zinc, and from iron, through water. The birds died within a few seconds, that 

 is, just as they did when their noses were unstopped. Quadrupeds were tried 

 after the same manner, and the event was the same. 



Having in this manner exploded this new hypothesis, there remained one 

 more, which seemed to suggest a probable reason, since some reason there must 

 be, for Mr. Scheel's experiments being attended with results so different from 

 those of other experimenters. When an animal is introduced into a vessel of 

 inflammable air, its whole body is exposed to that air ; and it is not yet known 

 by philosophers what disorders that fluid may occasion to the animal frame. It 

 is true that none are observed to be produced by other noxious kinds of air ; but 

 if it be considered, that the vapours of sulphur make a great impression on 

 frogs, even when those animals do not breathe them, but have their aspera ar- 

 teria tied up, it will not seem impossible for the inflammable air, in some way 

 or other, to act on the body of animals. It may perhaps hinder the perspira- 

 tion ; it may insinuate itself through the pores of the skin ; in short, its action 

 on the body seems probable till experiments evince the contrary. 



1 therefore endeavoured to force various four-footed animals to breathe the in- 



