ATTRACTION. 169 



(eee.) .Although, in general, there is no arithmetical ratio between 

 the combining proportions of different bodies, hydrogen forms an ex- 

 ception. According to Dr. Prout,* and Dr. Thomson, f "in -every 

 one of the compounds of hydrogen, the proportion of the body united 

 with it, is an exact multiple, by a whole number, of its own weight." J 

 Thus, in water, (protoxide of hydrogen,) the oxygen is just 8 times 

 the weight of the hydrogen, while in the deutoxide, it is 16 times ; and 

 in sulphuretted hydrogen, the sulphur is just 16 times the weight 

 of the 1 hydrogen. 



(fff') Berzelius^ has discovered that oxygen contained in different 

 proximate principles of the same compound, exists in a multiple ratio, 

 or in equality. Thus, hydrate of potassa is composed of potassa 48, 

 and of water 9, and there is 8 of oxygen in each of them. This law 

 holds in earthy minerals, containing several oxides, and in the salts. 



Carbonate of potassa consists of carbonic acid 22, containing oxy- 

 gen 16, and of potassa 48, containing oxygen 8. 



Where water of crystallization is present, there is a similar rela- 

 tion. Crystallized sulphate of soda contains sulphuric acid 40, in 

 which the oxygen is 24; soda 32, with oxygen 8, and water 90, 

 with oxygen 80; and these numbers, 8, 24, and 80, consist of one, 

 three, and ten proportions of oxygen. 



Compound salts obey the same law. In tartrate of potassa and 

 soda, the oxygen in the acid, and in the two alkalies is the same. 



(ggg.) " In each series of salts the same relation always exists 

 between the oxygen of the acid and of the base." In the neutral sul- 

 phates, the ratio is as 1 to 3 one in the alkali, and three in the acid. 

 In the carbonates the acid is double, and in the bi-carbonates, quad- 

 ruple the oxygen of the base. 



The illustrious discoverer of these most remarkable laws, says that 

 in the course of several years that have passed since he first observ- 

 ed them, he has not detected any exception, and he therefore relies 

 upon them implicitly, and is in the habit of calculating the compo- 

 sition of bodies upon this principle. || 



* Annals of Philosophy, Old Series, Vol. VI, p. 321. 



t First Principles. 



t This is denied by Berzelius, who asserts that it is inconsistent with the results of 

 his analysis. 



This account of the discoveries of Berzelius, is abridged from Dr. Turner s 

 Chemistry, 2d Ed. 



|| For an able view of this subject, see Dr. Turner's Chemistry, 2d Ed. p. 177. 

 He gives the following generalization. Most of the neutral sulphates, all the alka- 

 line and earthy, and several metallic sulphates of common metals, as iron, zinc, and 

 lead, consist of 1 proportion of acid, and 1 of base ; the acid contains 1 proportion of 

 sulphur, 16, and 3 of oxygen, 24, and every protoxide consists of metal 1 propor- 

 tion, and oxygen 1=8. It will be seen by comparing the numbers that 



1. " The oxygen of the acid is a multiple of that of the base." 



2 The acid contains three times as much oxygen as the base," 



22 



