1814.] Dallonlan Theonj of Dejlnite Proportions, 575 



Article VIII. 



On the Daltonlan Theory of Definite Vroponthm in Chemical 

 Combinations. By Thomas Thomson, M.D. F.R.S. 



{Conlinued from p. 134.) 



Iv preceding numbers of the Annals of Philosophy I have given 

 tables of the sulphates and nitrates as far as the experiment* 

 hithei'to made upon these bodies warrant us to go. 



It appears from the experiments of Berzelius that the sulphites 

 correspond exactly in their composition with the sidphates. Hence 

 the table given already for the sulphates will answer for the sulphites 

 likewise. We have only to substitute the number denoting an 

 integrant particle of sulphurous acid for the number which denotes 

 an integrant particle of sulphuric acid, or, which comes to the same 

 thing, we may subtract 1 from the number denoting the weight of 

 an integrant particle of each salt. 



The constituents of the nitrites have been too imperfectlv exa- 

 mined to enable us to draw up a table of these salts. A few of 

 them have been lately examined by Berzelius and Chevreuil ; but 

 the greater number are still unknown. 



I shall now give a table of the carbonates, a genus of salts of 

 considerable importance, and which have been examined with % 

 good deal of care. 



Genus llh—Carbonalesi 



Number of Weighl of an 



atoms. iolegrant particle. 



226 Bicarbonate of potasli ...2c + I p 11 '502 * 



227 Carbonate of potash ....1 c + 1 p ...... 8-751 '» 



228 Carbonate of soda 3 c + Is 16-135 *•" 



229 Subcarbonaie of soda ...2c + V s 13-38 i ** 



* According to this statement the salt ought to be a compound of 

 47'835 acid + 52-165 base. Now Berthollet's analysis gives us 

 47-64 acid + 52 36 base. (Jour, de Phys. Ixiv. I74.) The salt is 

 the common crystallized carbonate of the shops. 



'' Dr. VVollaston has shown that this salt contains just half the 

 acid that exists in the bicarbonate. 



*^ According to this statement it ought to consist of 39 acid + 

 37*247 base. Now Klaproth found it a compound of 39 acid + 38 

 base. 



•* According to tliis statement the salt ought to he composed of 

 \Q acid + 22-921 busi?. Now Ber^'inau obtained 16 acid + 20 



