190 Mr. C/dldren's Summarif View of [March, 



sulphuric acid, to contain six atoms of oxygen; but till new 

 facts ?how the probabihty of that supposition, there is sufficient 

 ground for considering the ratio to be that of 2 : 3. There is no 

 reason for supposing that two atoms of one element combine 

 with four, five, six, or a greater number of atoms of another 

 element, but in the varied productions of the mineral kingdom, 

 we find compounds somewhat different from those we can pro- 

 duce in our laboratories. Amongst the silicates, combinations, 

 in which three compound atoms of the first order are united to 

 four of the same order are frequent, as in laumonite, amphigene, 

 &c. ; but in our artificial productions, analogous cases are 

 extremely rare. 



As a general conclusion, we may assume, that in inorganic 

 compounds the simple atoms combine in very limited propor- 

 tions ; the most common is that of one atom of one element with 

 one or more atoms of another element, so that in most com- 

 pounds, one of the elements may be represented by unity : the 

 next most common proportion is that of two atoms of one 

 element to three of another; and in the mineral kingdom, in the 

 compound atoms of the third and fourth orders, we sometimes 

 meet with three atoms of one body united to four atoms of 

 another body. 



There is another law which, according to Berzelius, regulates 

 the combination of compound atoms of the first order ; namely, 

 that oxidated bodies always combine in such proportions that the 

 number of atoms of uxvuen in one of them is a midtiple by a 

 whole number of the number of atoms of oxygen \n the other; 

 and, in like manner, in the combinations of sulphuretted bodies, 

 the sulphur in one is a multiple by a whole number of the sulphur 

 in the other. Or, to express the law in general terms, compound 

 atoms of the first order, having a common electro-negative 

 element, coaibine in such proportion that the electro-negative 

 element of one atom is always a multiple by a whole number of 

 the electro-negative element of the other. 



The only known exceptions to this law are the acids of phos- 

 phorus, nitrogen, and arsenic, which combine with other oxidated 

 bodies in such proportion that the number of atoms of oxygen 

 in the oxide is one or more Jifths of the number of atoms of 

 oxygen in the phosphoric, nitric, and arsenic acids, and one or 

 two thirds of the same number in the phosphorous, nitrous, and 

 arsenious. 



When two salts, having a common acid but difl'ercnt bases, 

 combine, the number of atoms ofoxv<>en in one of the bases is a 

 multiple by a whole number of the number of atoms of oxygen 

 in the other ; and consequently the acid in one of the salts is a 

 multiple by a whole number of the acid in the other. In alum 

 and feldspar, the number of atoms of oxygen in the alumina is 

 triple the number of atoms of oxygen in the potash ; and in like 



