APPENDIX. 517 



pressed the importance of this study on many classes of the 

 community in lectures which have been separately published. 

 Thus he taught the farmers of the Highland and Agricultural 

 Society how deeply interested they are, or ought to be, in the 

 advance of the useful arts. He brought the subject before the 

 Pharmaceutical Chemists, and before the Company of Merchants, 

 urging on them their fourfold duty " to gather workable ma- 

 terials from the ends of the earth ; to send forth finished pro- 

 ducts, derived from these, to the four quarters of the heavens ; 

 to employ the most perfect mechanical and chemical appliances 

 which can change the one into the other, and facilitate their 

 transmission throughout the world; to encourage new arts, and 

 hope for still newer ones ; " and lastly, as a Christmas lesson, 

 he taught in the National Galleries the relation of ornamental 

 to industrial art, showing that while Beauty remains Beauty, the 

 Beast Utility may become " a graceful Prince, losing the clumsi- 

 ness, but keeping the strength of his former state, and Prince 

 and Princess join hands, each possessed of gifts which the other 

 has not. 'Not like to like, but like in difference." 



Not merely as Director, or rather collector of the Museum, 

 and as Professor of Technology, did Dr. Wilson advance the 

 cause of this science which he had made his own, but also as 

 President of the Eoyal Scottish Society of Arts. He found time 

 too for writing on such subjects : as, for instance, two papers 

 on Photography, 1 full of ingenious suggestions ; articles in the 

 ' Builder' on the Chemistry of Building Materials ; and a little 

 monograph on Paper, Pen, and Ink, which appeared in ' Mac - 

 millan's Magazine' for last November, the same month in which 

 ceased his labours for the material and mental advancement of 

 his brother men. 



1 On the Production of Photographs on Fluorescent Surfaces. ' Journal of Pho- 

 tographic Society.' 1857. 



On Dryness, Darkness, and Coldness as means of preserving Photographs from 

 fading. Ibid. 1859. 



Some of the theoretical views expressed in the first of these papers, relating to the 

 slight photographic effect of fluorescent substances, I have had the pleasure of proving 

 experimentally to be coi'rect. For some curious photographic observations of Dr. 

 Wilson, see also ' Cosmos,' Nov. 11, 1859, p. 543. J. H. G. 



