1844-54. SCIENTIFIC PAPERS. 337 



English translation of ' Lehmann's Physiological Chemistry,' by 

 Professor G. E. Day, special reference is made to them. 1 With 

 one or two exceptions, the papers containing a record of those 

 investigations were brought before the Royal Society, Edin- 

 burgh, and have a place in its Transactions. 2 The last notice of 

 the subject was one claiming priority, because of a communica- 

 tion made to the French Academy in 1856, by M. J. Nickles, 

 entitled ' Presence du Fluor dans le Sang,' this gentleman being 

 unaware, apparently, of Dr. Wilson's announcement of the same 

 fact in 1850. 



Before the Royal Society of Edinburgh were also brought, in 

 1848, the results of eight months' inquiry into the bleaching 

 powers of certain gases ; and in the following year the ' Early 

 History of the Air-Pump in England.' In 1845, he read also 

 here, ' On Wollaston's Argument from the Limitation of the 

 Atmosphere, as to the Finite Divisibility of 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 pos- 

 sible Derivation of the Diamond from Graphite and Anthra- 

 cite;' 3 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 consulted 

 with advantage by those interested in physiological pursuits. 

 It bears the impress of that careful thought and accurate rea- 

 soning which characterize all his writings. Of one or two other 

 papers presented to the Royal Society, Edinburgh, notice will be 

 found elsewhere. 4 



Before the Chemical Society of London were brought ' In- 

 quiries into the Decomposition of Water by Platinum ; ' the 

 ' Binary Theory of Salts ; ' and ' Some Phenomena of Capil- 

 lary Attraction.' 



Besides the more strictly scientific labours, of which some 



1 Vol. i. p. 425. Cav. Soc. Published 1852. 



2 A list of them will be found in the Appendix. 



3 See Appendix. 



4 See Appendix. 



Y 



