OF THE ATOMIC THEORY. 



we should expect one to be binary, two ternary, 

 and one quaternary, &c. 



(5.) A binary compound should be always 

 specifically heavier than the mere mixture of its 

 two ingredients. 



(6.) A ternary compound should be specifi- 

 cally heavier than the mixture of a binary, and a 

 simple, which would, if combined, constitute 

 it, &c. 

 5th and 6th With respect to these rules, the first four 



not accu- . , i i i i i 



rate. appear unexceptionable, unless the third should 

 be objected to ; but the fifth and the sixth do 

 not appear to be warranted by a review of the 

 compounds with which we are acquainted, com- 

 pared with their constituents. It is in general 

 true, that when two substances unite, they form 

 a compound whose specific gravity is greater 

 than the mean of that of the two constituents. 

 But to this there are many exceptions. Deutoxide 

 of azote has precisely the mean specific gravity 

 of the two constituents. It has been demon- 

 strated by Gay-Lussac, that it is composed of a 

 volume of oxygen gas and a volume of azotic 

 gas, united together without alteration of bulk. 

 One volume protoxide of azote + I volume of ox- 

 ygen gas united, will form 2 volumes of deutoxide 

 of azote ; so that in the act of uniting, an ex- 

 pansion instead of a contraction takes place. 

 The specific gravity of an alloy of 2 atoms tin 



