324 On the Definite Proportions in which the [Nov. 



ceive may be drawn from the experiments hitherto made. This will 

 enable the reader to judge whether the analytical results warrant my 

 conclusions in a satisfactory manner or not. 



I shall in the first place draw a comparison between the composi- 

 tion of inorganic and organic nature. The laws of inorganic com- 

 pounds may be expressed by the two following rules : — 



1. When two elementary bodies combine, they unite in such 

 proportions that one volume of the gas of one combines with an 

 equal volume of the gas of the other, or with two or with three 

 volumes of that gas, without any intermediate fractions ; and in 

 these combinations one of the elements ought always to he considered 

 as unity. 



According to the corpuscular theory, this means that an atom of 

 one of the elements combines with one or more entire atoms of the 

 other. We never find in inorganic nature combinations between 

 three atoms of one body and four or five atoms of another. We 

 find, on the contrary, that one of the elements exists in the state of 

 a single atom. This is one of the circumstances which chiefly 

 characterizes inorganic compounds. 



2. When two bodies, each containing oxygen, combine, the 

 oxygen in the one is always a multiple of that in the other by a 

 whole number. 



In all probability this law may be more generally expressed as 

 follows : — When two bodies having a common electro-negative 

 element combine, the electro-negative element of the one is always 

 a multiple of that in the other by a whole number. This is the 

 case, for example, with sulphur and arsenic in the double sul- 

 phurets and arseniurets, of which mineralogy presents us with so 

 great a number of examples. From these two rules all the others 

 may be deduced. 



In inorganic nature compound bodies of the first order* never 

 contain more than two elements ; so that we may say that inorganic 

 nature never contains more than binary combinations, and bodies 

 composed of binary combinations. 



All inorganic bodies in which we find more than two elements 

 are evidently composed of binary combinations of these elements, 

 which may be separated from each other without decomposition, 

 and generally they may be united again so as to form the compound 

 substance anew. 



The double or triple metallic sulphurets, which contain two or 

 three metals, are always to be considered as composed of as many 

 simple sulphurets. The alkaline sulphurets are to be considered as 



* By compounds of the first order, I mean bodies composed of elements, and 

 containing no constituent part which is a compound. Thus sulphuric acid is a 

 compound of (he first order. Sulphate of pota->h is one of the second, and alum 

 one of the third. For sulphate of potash is composed of two bodies of the first 

 orler, the acid and potash; and alum of two compounds of the second order, 

 namely, sulphate of potash and sulphate of alumina. See my memoir on the 

 Cau>c of Chemical l'roportious, jfnntlt of Philosophy, iii. 443, &c. 



