WOLLASTON. 143 



were contained in the ore of platinum, associated with osmium and 

 iridium, two metals discovered about the same time by Mr. Tennant. 

 In 1809 he showed that the supposed new metal, tantalum, was 

 identical with columhium, previously discovered by Mr. Hatchett; 

 and shortly before his death, he transmitted to the Royal Society a 

 communication, constituting the Bakerian lecture of 1828, in which 

 he fully describes his ingenius method of rendering platinum mal- 

 leable. From this invention he is stated to have acquired more 

 than 30,000?. 



Dr. Wollaston's knowledge was more varied, and his tastes less 

 exclusive, than any other philosopher of his time, except Cavendish ; 

 but optics and chemistry are the two sciences in which he made the 

 greatest discoveries. To him we owe the first demonstration of the 

 identity of galvanism and common electricity, and the first explana- 

 tion of the cause of the different phenomena exhibited by them. 

 Dr. Wollaston was accustomed to carry on his experiments in the 

 greatest seclusion, and with very few instruments ; he was also 

 endowed with an extreme neatness of hand, and invented the most 

 ingenious methods of determining the properties and constituents 

 of very minute quantities of matter. It is related by Dr. Paris (in 

 his Life of Davy), that a foreign philosopher once calling on Wol- 

 laston with letters of introduction, expressed a great desire to see 

 his laboratory. " Certainly," replied Wollaston, and immediately 

 produced a small tray, containing some glass tubes, a blowpipe, 

 two or three watch-glasses, a slip of platinum, and a few test- 

 tubes. 



Another anecdote is told of him, that, having been engaged one 

 day in inspecting a monster galvanic battery constructed by Mr. 

 Children, he accidentally met, on his way home, a brother chemist, 

 who knew of Mr. Children's grand machine, and uttered something 

 about the inconvenience of it being of such an enormous size ; on 

 this Wollaston seized his friend by the button, led him into a bye 

 corner, where, taking from his waistcoat pocket a tailor's thimble 

 which contained a galvanic arrangement, and pouring into it the 

 contents of a small phial, he astonished his friend by immediately 

 heating a platinum wire to a white heat. He also produced pla- 

 tinum wire so extremely fine as to be nearly imperceptible to the 

 naked eye. 



Towards the close of the year 1828, Wollaston became danger- 

 ously ill with disease of the brain. Feeling his end approaching, 

 and being unable to write himself, he employed an amanuensis to 

 write accounts of such of his discoveries and inventions as he was 

 unwilling should perish with him ; and in this manner some of his 

 most important papers were communicated to the Eoyal Society. 

 It is a curious fact, that, in spite of the extensive cerebral disease 

 under which he laboured, his faculties continued unclouded to the 

 very last. When almost at the point of death, one of his friends 



