APPENDIX. 519 



Wollaston, Black, Eobert Boyle, and Dalton. 1 His biographical 

 sketches, too, were not confined to chemists ; and at the period 

 of his death he was engaged on the memoir of his fellow-student 

 and colleague, the late Professor Edward Forbes. The only com- 

 plete biography, however, besides that of Cavendish, which we 

 possess from his pen, is that of Dr. John Eeid, and this is rather 

 a literary than a scientific work ; but it contains such a portrait 

 as could be only delineated by a man who at the same time felt 

 the interest of Dr. Eeid's physiological discoveries, and appreci- 

 ated his religious life. 



Dr. Wilson's attention was directed to the history of appara- 

 tus as well as of the inventors themselves, and he urged upon 

 his contemporaries the preservation of those models and actual 

 machines which represent the earliest forms of important en- 

 gines. 2 In 1849 he published a paper on the early history of 

 the air-pump in England, 3 with diagrams of the different ma- 

 chines, in which he rectified errors that other historians had 

 fallen into ; and those who were present at the opening of the 

 chemical section of the British Association at Aberdeen will re- 

 member the beautiful diagrams with which he covered the walls, 

 in illustration of his further researches in the same direction. 

 In another paper, 4 he claims as the earliest electrical machine, 

 not Otto von Guericke's famous sulphur ball, but an electrical 

 fish ; he points out the antiquity and generality of the practice 

 of using such fishes as remedial agents, and brings together an 

 immense store of information from many unheard-of sources re- 

 specting the Torpedo, the Silurus of the Mle, the Gymnotus, and 

 especially the Malapterurus Beninensis, which is found in the 

 muddy brackish waters of the rivers of Old Calabar, and appears 

 to be put by the native women into the tubs in which they wash 

 their children, in the belief that its shocks render them healthy 

 and strong. Under this head I may also class the paper on the 

 fruits of the Cucurbitacere and Crescentiacese, 5 in which he shows 



1 * British Quarterly Review.' 



2 See his Address as President of the Royal Society of Arts, 1857. 



3 < Edin. New Phil. Journal,' April 1849. 



4 On the Electrical Fishes, as the earliest Electric Machines employed by Mankind. 

 Edin. New Phil. Journal,' October 1857. 



s 'Trans. Bot. Soc. Edin.,' vol. vi. 



