326 On the Definite Proportions in which the [Nov. 



means excludes determinate proportions, because the ternary, &c. 

 ov.des are subjected to the same law of combination as the binary; 

 and this must be ascribed to the same cause in organic and inorganic 

 bodies; namely, to the existence of determinate pioportions in both 

 kingdoms or nature. 



I suppose that other chemists, as well as myself, have found it 

 difficult to conceive how such an immense variety of compounds 

 among three or four elementary bodies could exist conformat ly to 

 the. laws of chemical pioportions ; the different species o\ ege able 

 oils, for example, of tannin, ike. ; for it is to be supposed that the 

 difference in their composition is infinitely small ; bu. this difficulty 

 is obviated by the single circumstance that in these ternary, &c. 

 oxides, none of the elements is necessarily an unit; of consequence 

 the number of possible combinations becomes almost infinite. I 

 will endeavour to explain these circumstances by examples. It is 

 known that when an acid combines with a base, the acid always 

 contains two, three, &c. as many volumes of oxygen as the base ; 

 but 1 have endeavoured to prove (in my memoir on the Cause of, 

 Chemical Proportions,) that when an acid in these neutral salts 

 contains three times as much oxygen as the base, the acid is com- 

 posed of one volume of radicle and three of oxygen ; and even 

 supposing this not always to be the case, still the number of volumes 

 of oxygen in the acid is divisible by the number which expresses 

 how often the acid contains the oxygen of the base ; so that if the 

 same acid forms salts with an excess of base, it is very easy to find 

 how many volumes of oxygen the acid contains for one volume of 

 its radicle. For a more detailed explanation of that matter 1 refer 

 the reader to my memoir already quoted. 



Now if we apply these observations to the vegetable acids, we 

 find without much difficulty the number of volumes of oxygen 

 which they contain ; and this number being once known, it is easy 

 to determine by direct experiments what is the number of the 

 volumes of the other elements ; for example, 100 parts of tartaric 

 acid saturate a quantity of base which contains 11 -976 of oxygen. 

 This acid (by an analysis which I shall detail below) contains 59\S8 

 per cent, of oxygen, 36-167 or carbon, and 3 951 of hydiogen. 

 If we state these numbers in volumes, we get 1 of carbon, 1-i- of 

 oxygen, and 1^- hydrogen; but the oxygen in the acid is exactly 

 five times that in the base which it neutralizes. Hence we must 

 suppose that the acid contains five volumes of oxygen. On this 

 supposition the fractions disappear, and the acid is a compound of 



4 volumes carbon 



5 oxygen 



5 hydrogen 



100 parts of succinic acid saturate a quantity of base containing 

 15-9J5 of oxygen ; but with oxide of lead, besides the neutral 

 succinate, it forms a subsalt, in which it is combined with three 

 times as much oxide as in the neutral combination. Hence succinic 



