60 ESSAYS BIOGRAPHICAL AND CHEMICAL 



victorious, with leisure to resume the scientific work 

 which the state of warfare had interrupted. In this 

 office he remained until his death, which took place in 

 1869. 



Unlike Davy, Graham was of a modest and retiring 

 disposition. His gentleness endeared him to all those 

 whom he admitted within the circle of his friends ; and 

 his calm judgment rendered him an invaluable counsellor. 

 Yet he received his full meed of honour ; he was the first 

 president of the Chemical Society ; a Fellow of the Royal 

 Society; the 'Keith' Medallist of the Royal Society of 

 Edinburgh; he twice received a Royal Medal of the 

 Royal Society of London, and in 1862 the Copley Medal, 

 given as the reward of a life successfully devoted to 

 scientific discovery ; he was a Corresponding Member of 

 the Institute of France; and he received from that 

 august body the Prix JecJcer. 



Graham's scientific work admits of division into two 

 groups, one relating to the physical behaviour of gases 

 and liquids, and the other to the constitution of salts. 

 Besides papers on these subjects, he published a number 

 of miscellaneous papers. 



In the second of these groups, his earliest communica- 

 tion was on the existence of compounds containing 

 alcohol of crystallisation, analogous to the well-known 

 water of crystallisation. The analogy between water and 

 alcohol was thus shown ; an analogy which, in the hands 

 of his successor Williamson, played an important part in 

 the development of modern views on the constitution of 

 the carbon compounds, and indirectly on the whole of 

 chemistry. In 1833, Graham published his remarkable 

 memoir on the phosphoric acids, in which he argued that 

 as alcohol could replace water in hydrated salts, so water 

 could replace bases, in such salts as the phosphates. 

 The acids of phosphorus had previously been a puzzle to 



