134 Of the insalubrity of FLAT 



as the blood recovered its florid colour from the applica- 

 tion of pure air. 



In thefe experiments, all the other fundlions of the 

 body were obferved to be proportionally affedled with 

 the heart. As its contractions diminifhed, the power of 

 thefe alfo declined : As the power of the heart recovered, 

 thefe alfo recovered. 



By thefe experiments, we learn that the abflraftion or 

 exclufion of the oxygenous part of the atmofphere, in a 

 given fpace is fufficient of itfelf to deprive animals of life 

 by withholding the caufe of adion. Hence we are 

 authorifed by the chaflefl rules of induction to conclude 

 that health and life muft be affected more or lefs in pro- 

 portion to the quantity of this vivifying principle at any 

 time abftraded from the atmofphere, which more im- 

 mediately furrounds us. 



The prefence of the other component part of the at- 

 mofphere, the bafe of the azotic gas though totally op» 

 jjofite to the oxygen with which it forms a perfedt com- 

 pound, and neutral fubftance when mixed in the pro- 

 portions already mentioned, appears to have no fhare in 

 deftroying life, though its name is derived from a mif- 

 taken fuppofition that it had that eife£t ; for the heart 

 immerfed in this gas, will retain its irritability feveral 

 hours, in a warm fituation, after all figns of life have dis- 

 appeared in the reft of the body. Mr. Valli's experi- 

 ments on animal eledrieity have eftablillied this faft. 



Carbonic gas or fixed air, on the contrary, produces 

 its deftrudive tfi'eds by a dired operation, for it deftroys 

 the nervous power and the irritability of the mufcular 

 fibres the inftant that it is received into the lungs, and 

 comes in contad: with the heart. 



If the carbonic gas operated, as fuggefted by Mr. Kite, 

 by inducing a fpafm of the glottis and thereby excluding 

 the atmofpheric air, the heart as in other cafes of fuf- 



pended 



