OF THE ATOMIC THEORY. 37 



Carburetted hydrogen is a ternary compound, 

 composed of 1 atom carbon and 2 atoms 

 hydrogen : deutoxide of azote is a ternary -com- 

 pound, composed of 1 atom azote and 2 atoms 

 oxygen. Ammonia is a quaternary compound, 

 consisting of 1 atom azote and 3 atoms hydro- 

 gen ; sulphuric acid is a quaternary compound, 

 composed of 1 atom sulphur and 3 atoms oxy- 

 gen. Nitrous acid is a quinquenary compound, 

 composed of 1 atom azote and 4 atoms oxygen. 

 Nitric acid is a septenary compound, composed 

 of 1 atom azote and 5 atoms oxygen. After 

 these illustrations the terms septenary, octonary, 

 &c. will be understood without any farther 

 explanation. 



Mr. Dalton lays down the following rules, by Mr. Dai- 

 which he thinks we should be guided in our 

 opinions respecting chemical synthesis. 



(1.) When only one combination of two 

 bodies can be obtained, it must be presumed to 

 be a Unary one, unless some cause appear to 

 the contrary. 



(2.) When two combinations are observed, 

 they must be presumed to be a binary and a 

 ternary. 



(3.) When three combinations are obtained, 

 we may expect one to be a binary and the other 

 two ternary. 



(4.) When four combinations are observed, 



C3 



