ON ATMOSPHERICAL AIR. HI 



clent to faturate the fame quantity of nitrous gas. The data 

 of the following calculation are taken partly from the one and 

 partly from the other author : I have fuppofed with M. La- 

 voifier, that three inches of the oxigenous will acidify 13 

 inches of the nitrous gas : M. Chaptal is followed in other re- 

 fpeds^ namely, the atmofphere is imagined to contain 72 per 

 cent, of azote, and S9 inches of air are made equivalent to 52 

 of nitrous gas. The calculation, which is formed upon thefe 

 fuppofitions, will in all probability prove incorred j but I have 

 ventured to infert it, as being a novelty, which is likely to 

 excite enquiry. If 39 inches of air can faturate 52 of nitrous 

 gas, 100 inches of the former require 133.333 of the latter. 

 Again, if 13 inches of nitrous gas demand three of oxigen, 

 133.333 of the former will require 30.303 of the latter. But 

 the weight of 30.303 inches of oxigen gas amounts to 10.361 

 grains, which is equivalent in effect to 100 inches of air. 

 Now 72 fnthfef of azotic gas weigh 21.985 grains, which 

 being taken from 31 grains, leaves 9.015 grains for the weight 

 of the oxigenous part of 100 inches of air; in round numbers, 

 90 grains of the latter kind of oxigen are equal in effedl to 

 103 of the former.. 



I know that M. Lavolfier, in fpeaking of the conflitution 

 of nitric acid, makes 100 grains of it contain 64 grains of the 

 nitrous and 36 of the oxigenous gas ; or 173 inches of the 

 former and 105 of the latter. Had the data of the preceding 

 calculation been taken from this ratio, the comparative fupe- 

 riority of atmofpherical oxigen would have been much greater 

 than it appears to be by the lafl paragraph. A preference, 

 bowever, has been given to the preceding hypothefis, becaufe 

 I defire to excite enquiry, rather than exped to eftablifh any , 

 thing of a permanent nature concerning the fubjed. 



The preceding arguments, in conjun6lion with others of a The origin of 

 kind more uncertain than themfelves, fiiggefted to me the ^j^^ phlll^ro^r. 

 probability of atmofpherical oxigen pOiTeffing a greater degree vol. viii. p. 246. 

 of efficacy than an equal weight of vital air. This idea oc- 

 curred to me feveral months ago ; and I at length refolved to 

 propofe it to the public in a number of hypothetical queftions, 

 which appeared in your Journal for Auguft. Thefe queries 

 are evidently borrowed from fome ingenious fpeculations, that 

 were publiflied in the eighth volume of the fame work*; for 



' ' * Page 8S. v"'-- 



the 



