1 88 MEMOIR OF GEORGE WILSON. CHAP. VIII. 



Matter ; " later, " On the Organs in which Lead accumulates 

 in the Horse, in cases of slow poisoning by that metal ; " 

 and in 1850, " On the possible Derivation of the Diamond 

 from Graphite and Anthracite ; " while on another occasion 

 he brought forward attempts to trace the source of Nitrogen 

 in Plants. 



Phenomena of vision, encountered while prosecuting the 

 researches in colour-blindness, led to observations " On the 

 Extent to which the received Theory of Vision requires us 

 to regard the eye as a Camera Obscura," which may be con- 

 sulted with advantage by those interested in physiological 

 pursuits. It bears the impress of that careful thought and 

 accurate reasoning which characterise all his writings. Of 

 one or two other papers presented to the Royal Society, 

 Edinburgh, notice will be found elsewhere. 



Before the Chemical Society of London were brought 

 " Inquiries into the Decomposition of Water by Platinum ; " 

 the " Binary Theory of Salts ; " and " Some Phenomena of 

 Capillary Attraction." 



Besides the more strictly scientific labours, of which some 

 notice has been given, he found time to draw up a series ot 

 essays for the "British Quarterly Review," between 1845 

 and 1849, which have justly been reckoned as successful as 

 anything he ever wrote. "The paper on Chemistry and 

 Natural Theology boldly grapples with the difficulty arising 

 from the presence of evil as well as good in the manifesta- 

 tions of design, and contains a vivid reflection of his own 

 ^ experience of suffering ; while the scientific memoirs on 

 Dalton, Cavendish, Black, Priestley, Wollaston, and Boyle, 

 show a range of reading and a power of elucidation not 

 often combined in the treatment of any science." 1 After 

 reading some of them, Lord Jeffrey wrote to a friend, saying, 

 i "Macmillan's Magazine," January 1860. 



