510 MEMOIR OF GEORGE WILSON, 



which others have pursued to a successful issue. Thus he had 

 great influence on the science of the day, though he never added 

 to the list of chemical compounds, which is now growing to 

 such portentous dimensions, or made any anatomical discoveries. 



His first investigation was his boldest, and that farthest re- 

 moved from ordinary human interest. In chemistry there has 

 long been a notable question, What becomes of a Haloid salt 

 in solution ; or, to take a particular instance, when common 

 salt dissolves in water, does it remain chloride of sodium, or 

 does it become hydrochlorate of soda ? Dr. Wilson, when a 

 student, thought he had solved this riddle. He communicated 

 his discovery to the British Association, and published his 

 ' Experimental Demonstration of the Existence of Haloid Salts 

 in Solution,' 1 resting mainly on the fact that hydrobromic acid 

 dissolved in water with terchloride of gold produces the scarlet 

 bromide of that metal. The argument in the then state of 

 chemical knowledge was perhaps unanswerable ; but, from 

 frequent communications with him on the subject in later years, 

 I know that he altered his opinion of its conclusiveness. He 

 brought the matter again before the British Association in 1855, 

 with further experiments, and in the meantime he had published 

 a paper on "The Argument for the Binary Theory of Salts, 

 derived from the non-action of the anhydrous oxygen acids on 

 organic colours." 2 



In the early part of Dr. Wilson's career, his fellow- student 



1 This is to be found in the ' Edinburgh Academic Annual ' for 1839. It formed 

 part of one of the Inaugural Dissertations, selected by the Faculty of Medicine to 

 compete for their annual gold medal at the public graduation, August 1, 1839. 



2 ' Quarterly Journal of the Chemical Society,' vol. i. p. 332. In a letter to 

 Dr. Gladstone in May 1855, Dr. Wilson speaks of this inquiry while referring to a 

 paper of Dr. Gladstone's, ' On Circumstances Modifying the Action of Chemical 

 Affinity.' (See Phil. Trans, for 1855.) "As for the Salt question, remember 

 that my paper was written so far back as 1837, when I was a student, and that 

 the Berthollet doctrines of affinity, although pleaded for by Professor Graham, were 

 not appreciated as your papers will now lead them to be. Graham himself volunteered 

 his adhesion to my views at the British Association meeting of 1839, so little did he 

 think of questioning them by such reasonings as yours. I did not purpose to call 

 in question the general justness of your conclusions. On the other hand, I fully 

 admit and admire them, and freely acknowledge that my inferences must be modified 

 in the light of your views, which are far beyond and above Berthollet's in many 

 respects. At the same time, I think my conclusions substantially unaffected, and 

 that your recognition of what our older chemists called ' Elective Affinity' occurring 

 according to the law of equivalents, leaves me all I demand." J. A. W. 



