1820.] the Atomic Theory. 211 



oxygen is to 12-641 weight of carbon; so is 1, weight of an 

 atom of oxygen to -765 weight of the atom of carbon. 



The weights 46-313 and 29- 158 may be readily deduced from 

 the specific gravity of those gases. 



The specific gravity of carbonic gas = 1-519 ; that of carbonic 

 oxide = 0-956 : now 



I : 30-5 :: 1-519 : 46-313 

 1 : 30-5 :: 0-956 : 29-158 



i. e. 1, the specific gravity of atmospheric air is to 30-5, weight 

 of 100 cubic inches of atmospheric air, as 1-519 specific gravity: 

 of carbonic gas is to 46-313 weight ot 100 cubic inches of the 



same gas 



41. Nitrogen. — There are five compounds of nitrogen and 

 oxygen gas, which it is necessary to examine, the better to 

 determine the weight of the atom of nitrogen. 



1. Protoxide of nitrogen or nitrous oxide gas. It is composed 

 of two volumes of nitrogen and one volume of oxygen. Now 

 one volume, say 100 cubic inches, of oxygen weighs 33-888 grs. 

 and two volumes, or 200 cubic inches of nitrogen, weigh 29-652 



X 2 = 59-304 grs.; therefore the protoxide weighs the sum of 

 their weights, 33-888 + 59-304 = 93-272 grs. To find_the 

 weight of each constituent in 100 grs. as the compound 93-272 is 

 to 33-888, its proportion of oxygen ; so is the compound 100 

 grs. to 36-3 grs. the oxygen in 100 of the protoxide. Conse- 

 quently 100 — 36-3 = 63-7, the nitrogen in 100 protoxide. 



Protoxide 63-7 nitrogen 



36-3 oxygen 



100-0 



2. Deutoxide, or nitrous gas, composed of one volume nitro- 

 gen and one volume oxygen. 



The volumes of nitrogen and oxygen weigh as above 29-652 

 -f- 33-888 = 63-540, and to find the weight of each constituent 

 in 100 of nitrous gas 63-540 : 33-888 :: 100 : 53-33 oxygen, and 

 100 - 53-33 = 46-67 nitrogen. 



Now let the base, or nitrogen, be the same, = 63-7 in all the 

 combinations of nitrogen and oxygen, and then as 46-67 nitrogen 

 : 53-33 oxygen :: 63-7 nitrogen in the protoxide : 72-7 oxygen in 

 the deutoxide or nitrous gas. It is evident from this, that the 

 oxygen in the nitrous gas is double that in the protoxide, for 

 72-7 = 36-3 X 2. 



3. Hi/ponitroitaAcid.—Thls acid, discovered by Thenard, and 

 by him called pernitrous acid, is composed of 175 nitrogen and 

 300 oxygen by weight. Then to find the oxygen, the nitrogen 

 being the same as that of the protoxide 63-7 ; as 175 : 300 :. 

 63-7 : 109-2. This shows that the oxygen in the hyponitrous 



o2 



