204 1 LETTER CONCERNING PALLADIUM. 



The whole inftrument is fixed upon a mahogany table, 

 which ferves as a (land to it. 



I will conclude by observing, that neither the employing 

 of glafs cylinders, or the method of opening the valves, are 

 new, but, for aught I know, this is the firft inftrument of 

 the kind ever executed in this country ; as likewife the idea 

 of putting the valves at top, and thus amplifying the inftru- 

 ment, feems to have efcaped the attention of the eminent 

 artifts both here and abroad ; as to my belt knowledge, it has 

 never been done or defcribed any where. The metallic pif- 

 tons, without leathering, mutt certainly add to the durability, 

 and diminifh the great labour that ufually attends working an 

 air-pump. 



IX. 



Letter concerning Patladium> from William Hyde Wol~ 

 laston, M. D. F. R. S. the Dfcovercr of that Metallic Body. 



To Mr. NICHOLSON. 

 SIR, 



The author 1 HE candour with which you communicated all circum- 



proceedines°™ er ^ ances ^ at came to vour knowledge concerning palladium, 

 fpeding pal- at a time when the difcoverer of that fubftance was yet un- 

 £?hVdif Wchknown t0 )' ou ' demands my earlieft acknowledgments as 

 covercr. having been the author of thofe communications; and it is 



proper that I (liould alfo exprefs the fatisfaction I received on 

 learning the refpe6tab!e tribunal you nominated at my requefr, 

 for examining the merits of any attempts that might be made 

 to form that fubftance artificially. 

 Reafons why the As I have already (hewn (in a paper which you did me the 

 chfeovery w»s nonour t reprint in your Journal for January laft, p. 3t,) 

 ed to the world by what means a very fmall quantity of Palladium may be 

 anonymouily. extracted from the ore of platina, and as I have there examin- 

 ed the fynthetic attempts to prove that this body was a com- 

 pound, with a degree of attention which I thought due to 

 the chemical (kill of the perfon who. propofed them, as well 

 as to the degree of uncertainty that muft attend a fubject 

 entirely new ; I cannot now adduce further chemical evidence 

 and can only add, for the information of thofe whofe judgment 

 has been biafTed by the difficulty of accounting for the pro. 



duction; 



1 



