On a new Metal, found in crude Plathm. 169 



(A 2.) Having in one instance dissolved such a precipitate 

 in nitro-muriatic acid, and precipitated the platina by yal 

 ammoniac, I suffered the remaining fluid to evaporate with- 

 out heat; and obtained a mixture of various crystals, very 

 ditierent from each other in form and colour. From these, 

 I selected for examination some that were of a deep red 

 colour, partly in thin plates adhering to the sides of the 

 vessel, and partly in the form of square prisms having a 

 rectangular termination. 



(A3.) A portion of these crystals being heated in a small 

 tube, yielded sal ammoniac by sublimation, and left a black 

 residuum, which, by greater heat, acquired a brilliant me- 

 tallic whiteness, but could not be fused under the blow- 

 pipe. Having obtained this substance from a distinctly crv- 

 stallized salt, I was inclined to consider it as a simple 

 inetal ; and, as I found it to be wholly insoluble in nitro- 

 muriatic acid, I judged it not to be platina. 



(A 4.) I'he crystals also, instead of being nearly insolu- 

 ble, like the ainmoniaco-muriate of platina, were dissolved 

 in a small quantity of water, and gave a ro!>c-colourcd solu- 

 tion . Upon mixing this with a solution of platina, the 

 ammonia was transferred by superior allinitv to the latter, 

 forming an ammoniaco-niuriate of platina; and the precipi- 

 tate was of a yellow colour. Consequently, the metal con- 

 tained in the salt was neither platina, nor that which gives 

 the red colour to the salts of platina. 



It would be useless to detail my first unsuccessful experi- 

 ments, made upon the properties of this metal, in hopes of 

 disco\-ering means by which its separation from platina 

 might be effected; I shall therefore confine myself to the 

 following process, which apjsears to be the most direct for 

 procuring rhodium in a state of purity. In the same process 

 also palladium is obtained, so as to atl'ord a presumption, 

 that it is rather a natural simple body than any artificial 

 compound. 



' (B 1.) Since the platina to be procured in this country 

 generally contains small scales of gold intermixed, as well as 

 4 portion of the mercury which the Spaniards employ for the 

 separation of the gold, the platina used for my cxperinu;nts, 

 after being by niechanical means freed, as far as possible, 

 from ail visible impurities, was exposed to a red heat, for 

 the purpose of expelling the mercury. It was then digested 

 for some time in a small quantity of dilute nitro-muriatic 

 jieid, and frequently shaken, till the whole of the gold was 

 dissolved, togetiier with any impurities that miiiht super- 

 ticially adhere to tlui crains of platina. 



(Be.) 



