Biographical Account of Dr. M'ollaston, hij De. Tuomas Thomson. 139 



for not intrusting the secret to Mr. Chenevix, he assured me that he had 

 done all in his power to convince Chenevix that he was mistaken — that 

 he had written him, assuring him that he himself had repeated Mr. Chene- 

 vix's experiments and found them inacciarate, and that he himself was 

 satisfied, from careful examination, that palladium was a distinct metal. 

 I have no doubt that WoUaston's statement is correct, but think that he 

 ought not to have allowed Mr. Chenevix to publish his paper, without 

 betraying the secret of the discovery of palladium, and the reasons which 

 induced him to believe that palladium was a peculiar metal. Chenevix 

 had been occupied at the rate of fourteen hours a day for nearly a quarter 

 of a year. It is not surprising that he was not likely to yield to a set of 

 experiments diifering from his own. But the eifect of Dr. WoUaston's 

 conduct was to destroy the chemical reputation of Chenevix, and put an 

 end to the chemical career of one of the most active and laborious che- 

 mists of his time. 



In the Philosophical Transactions for 1804, Dr. WoUaston published 

 an account of the properties of palladium, and pointed out the mistake 

 into which Chenevix had fallen. In the same paper he described the 

 properties of another new metal which he had found in crude platinum, 

 and to which he gave the name of rJwclium. 



It will be worth while to take a short review of Dr. WoUaston's che- 

 mical papers, published in the PhUosophical Transactions, that we may 

 see the discoveries for which chemistry is indebted to him. 



1. The earliest of these discoveries, though the last given to the che- 

 mical world, was the method of rendering platinum maUeable and ductile. 

 It furnished practical chemists with a most important utensil, to which 

 chemistry is indebted for the great degree of perfection to which chemical 

 analysis of minerals has reached. Every body now can analyse a mineral 

 with tolerable accuracy; but before Dr. WoUaston supplied a platinum 

 crucible, the analysis of the simplest mineral was a work attended with 

 great labour, and a great waste of time. 



AU the great improvements in chemistry were preceded by the dis- 

 covery of certain utensils, which, when applied to chemistry, developed a 

 new series of important facts. The pneumatic apparatus contrived by 

 Cavendish and Priestley, led to the discovery and examination of numer- 

 ous elastic fluids which had hitherto escaped the attention of chemists. 

 Dr. WoUaston's platinum crucibles speedily brought the art of analysing 

 minerals to a state of perfection. The discovery of the galvanic battery, 

 and the decomposing power of electricity, led Davy to the discovery of 

 the constitution of the fixed alkalies, alkaline earths and earths proper, 

 which had previously been considered as simple substances. The simpli- 

 fication and perfection by Liebig of the apparatus contrived by Gay Lussac 

 and Thenard for the analysis of vegetable bodies, led immediately to the 

 examination of an immense number of substances of vegetable origin, and 

 the discovery of numerous interesting and important bodies which had 

 hitherto escaped the attention of chemists, 



