1820.] the Atomic Theory. 205 



have been conducted with the greatest care, and by the ablest 

 experimenters, approach the closest to the conclusions of the 

 theory. The moment it is unequivocally entitled to confidence, 

 it becomes of the greatest assistance to the practical chemist; 

 for, by determining one or two constituents of a compound, 

 others will be had from calculation with as much certainty as 

 we can get the inaccessible side of a triangle from two angles 

 and one other side. 



25. The proportions in which the elementary atoms unite are 

 very limited ; almost the whole of them have been examined 

 without Hnding an exception to the law of their combination. 

 Elementary atoms when they combine, form compound molecules 

 of the first order ; when these unite, they form compound mole- 

 cules of the second order. The combinations of the latter are 

 greatly diversified, varying in their elements as to the number of 

 coQipound atoms which they contain. Berzelius examined a 

 vast number of these substances, and as they are for the most 

 part composed of oxides, he paid particular attention to the 

 oxygen they contain. 



From the numerous analytical researches of this eminent phi- 

 losopher, aided by those of Gay-Lussac, and several other 

 distinguished chemists, certain canons have been deduced which 

 are strictly conformable to the atomic theory, and render its 

 apphcations exceedingly l)eneficialto the operative chemist. 



26. When gaseous bodies combine, they always unite ia 

 determinate proportions ; and if we represent the bulk of the 

 gas that enters into the compound in the smallest quantity ia 

 bulk by 1, then the bulk of the other constituent is either 1, 2, 

 or 3, &c. Thus, muriate of ammonia is composed of 1 muriatic 

 gas + 1 ammoniacal gas ; carbonate of ammonia of 1 carbonic 

 acid gas + 1 ammoniacal gas ; nitrous gas of 1 nitrogen -f- 1 

 oxygen ; water of 1 oxygen + 2 hydrogen ; nitrous acid of 

 1 nitrogen + 2 oxygen ; sulphuric acid of 1 oxygen + 2 sulphu- 

 rous acid gas, because the sulphurous acid gas consists of 

 1 sulphur + '2 oxygen, carbonic acid of 1 oxygen + 2 gaseous 

 oxide of carbon, for the latter is formed of 1 carbon + 1 oxygen; 

 ammonia of 1 nitrogen + 3 hydrogen. This canon has beea 

 established by Gay-Lussac in a satisfactory manner. 



The same result is observable in all the compounds of inorga- 

 nic matter, one of the constituents of which is uniformly in the 

 state of a single atom. This law greatly simplifies the doctrine 

 of atomic combinations, as far as inorganic bodies are concerned, 

 and reduces the whole to a state of elementary facility. 



27. The quantity of acid requisite to saturate the different 

 metals is directly as the quantity of oxygen which these metals 

 require to convert them into oxides. Thus 100 parts of merituiy 

 require 4-16 parts of oxygen, and 100 parts of silver require 

 7'y parts of oxygen, to convert them into oxides. Therefore, the 



