102 



partment of analysis : but the process adopted by Mr, Talbot is more 

 allied to that followed by Fagnani than by Abel, and is equally re- 

 markable for its great simplicity and for the vast number of novel 

 and interesting results which it furnishes, including not merely several 

 of the most remarkable of those which are already known, but like- 

 wise many others which are apparently not deducible by other 

 methods. 



The Council have awarded the Royal Medal for Chemistry to 

 Professor Thomas Graham for his paper entitled " Inquiries respect- 

 ing the Constitution of Salts ; of Oxalates, Nitrates, Phosphates, 

 Sulphates, and Chlorides," which was read to the Society on the ^^th 

 of November 1836, and since published in the Philosophical Trans- 

 actions. This paper they have considered as being the last of a 

 series on a general subject of great importance : and as the sequel 

 of Professor Graham's researches on the Arseniates, Phosphates, and 

 modifications of Phosphoric Acid, read to the Society on the 19th 

 of June 1833, and published in the Philosophical Transactions of 

 the same year. He has therein shown that, by considering the 

 water which enters into the composition of the different classes of 

 salts, which the phosphoric acid forms with the several bases, and 

 which has been considered as water of crystallization as standing in 

 a basic relation to the acid, a very simple view might be taken of 

 this very complicated subject. According to this theory, there are 

 three sets of phosphates, in which the oxygen of the acid being 5, 

 the oxygen in the base is respectively 3, 2, or 1 ; the remaining 

 equivalents of oxygen, in the two first cases, being supplied by that 

 portion which exists in the 2 or 3 equivalents, respectively, of the 

 basic water, which water is wholly absent in the third case. These 

 three classes of salts Professor Graham proposes to term, respect- 

 ively, monobasic, bibasic, and tribasic salts. Professor Graham has 

 extended these views of the basic formation of water in salts to the 

 case of the sulphates, in a paper communicated to the Royal Soci- 

 ety of Edinburgh, and published in the 13th volume of their Trans- 

 actions, on " Water as a constituent of Salts." The principal ob- 

 ject of this paper, however, was to show that water exists in a dif- 

 ferent state in certain salts, and does not exercise a true basic func- 

 tion, being capable of being replaced by a salt, and not by an alka- 

 line base, and giving rise to a class of double salts. This inquiry 

 was suggested by the tendency of phosphate of soda to unite with 

 an additional dose of soda, and form a subsalt,wh\ch. had been traced 

 to the existence of basic water in the former. The result was, that 

 in the well-known class of sulphates, consisting of sulphates of mag- 

 nesia, zinc, iron, manganese, copper, nickel and cobalt, all of which 

 crystallize with either five or seven equivalents of water, one equi- 

 valent proved to be much more strongly united to the salt than the 

 other four or six. The latter, to which the name of water of cry- 

 stallization should be restricted, may generally be expelled by a heat 

 under the boiling point of water ; while the remaining equivalent 

 uniformly requires a heat above 400° of Fahrenheit for its expul- 



