Ohfervat'tons on the Ipomcsa Hifp'idd. 1 1 



a defire to be ufeful, obfervers abler than myfelf, and more 

 favoured bv circuniftances, will no doubt finifli what I havu 

 onlv ftctched out. 



XVII. To encourao-e them, and fliow them the probabi- 

 lity of the mod brilliant fuccefs, let me be permitted to fay 

 a few words refpeftiug two properties equnlly conimon to 

 animals and vegetables, from which life and fenfatioii feem 

 to flow — I mean generation and refpi ration^ fo necelfary to 

 thefe two kinds of organized beings. 



XVIII. Air is an element fo neceflary to animal life, that 

 it becomes weakened, and is at length extinguilhed, when 

 entirely deprived of it; and from my own obfervations I am 

 induced to believe that no animal can live without^ air, and 

 without a quantity, more or lefs confiderable, of oxygen; 

 though we are but imperfectly acquainted with the manner 

 in which it acfs, how it is refjnred by the different animals, 

 and bv what means they are able to feparate it from the dif- 

 ferent' fubttances with which it is united, and which caa 

 more or lefs alter its purity. 



XIX. What is certain is, that fmall eels, fufceptible of 

 being recalled to life, die if deprived of air, or if care be not 

 taken to renew it ; and it would be loft labour to attempt to 

 reanimate them, if the water in which they are immeried is 

 not in contact with refpirable air. They live only a very 

 fliort time in every kind of water deprived of that air. They 

 die in hydrogen and nitrogen ; though thefe gafcs are not 

 prejudicial to them of thcmfclves; and do not occalion to 

 tliem fuddcn death, like the greater part of the other gafes, 

 without even excepting carbonic acid gas. It appears, then, 

 that oxygen contains the vital principle; and the principle it 

 has of maintaining and preferving life, induces us to believe 

 that if it does not communicate it dirc6lly, it can at lead 

 awaken it, and put it in action. The fmall animals above 

 mentioned are an irrefragable proof of this afl'ertion. They 

 remain dead as long as they are deprived of oxygen, but its 

 prefcncc innnediaterv rellores them to life and motion. It 

 may therefore be faid that it contains the direft principle of 

 life, which it inlui'cs into them ; or that their vital organs, , 

 in order to be reanimated, ftood in need only of this aliment, 

 of which they were deprived. 



XX. The abfolute need which plants have of air in order 

 to vegetate and be preferved, renders it highly probable tliat 

 it ferves for the fame purjiofes among animals ; and that it 

 ought to be confidered in thefe two clafles of beings as a 

 prineijile from which life flows, in the fame niamier as an 

 elftdt IVum il^ cuufc. Befides, vegetables arc organized as 



B 3 ^ well 



