14* DESCRIPTION OF A NEW PROCESS OP REFINING. 



ric of 66° as will cover its furface ; I increafe the temperature 

 of this acid by placing my veflH on a fand-bath, I raife it to 

 ebullition, and keep it in that ftate for about an hour ; I then 



gndwajbcd. fuffer the whole to cool *, I decant the acid and wafli the gold 

 until the water from the warnings will not yield any more pre- 



It is then pure, cipitate with muriatic acid or alkalies. Nothing then remains 

 but to dry this gold, which is in powder, and to reduce it into 

 ingots, which will constantly be of the purity of 1.000, or 24 

 carats. 



Thefe are all the details neceflary to direct the performance 

 of the operation which I propofe : the following are the ad- 

 vantages which I believe is actually pofleffes. 



Advantages of I make nopoujje, consequently I fave both charcoal and cru- 



the new procefs. cibJes . j ^ am enab j ed to per f orm t h e operation without 



pounding the metal fo often, and have fewer warnings and 

 meltings : but the greateft advantage of this improvement is 

 the considerable diminution of the fire left in the fcoria? ; for 

 in the former method the great quantity of nitrate of potafh 

 that was added, promoted the oxidation f, or the extreme di- 

 vifionof a confiderable part, of the filver, which then remained 

 in the fcoriae with the oxide of copper, the potafti, &c. and 

 this wafte amounted, in each operation, to 2400 grammes on 

 filver of the purity of .350 to .400. ; and this filver remained, 

 without yielding any profit, frequently for feveral years ; that 

 is to fay, until the time when the refiner had a fufficient quan- 

 tity of wafhings to make it worth refining. 



I have already afTerted that I conftantly obtain the gold in 

 its greateft purity, or at 1.000. which is known to be a great 



* I muft alfo obferve that it is efTential to fuffer thefulphuric acid 

 boiled with the gold, to be completely cold before it is decanted, 

 without this precaution, as the ftone-ware veffels ufed in France are 

 not capable of withftanding the great degree of heat acquired by the 

 acid in boiling, there is much hazard of being wounded by the frac- 

 ture of the veffels, and the drops of acid which are fcattered in all 

 directions; 



For greater fafety, the bottom of the vefTel may be covered with 

 fiilphuric acid of 66 degrees, and at the temperature of the at- 

 mofphere. 



f I dare not yet affirm that the filver is in the ftate of the fcorae 

 of the poujfeei I wait the refult of feveral experiments which I have 

 undertaken on this fubjec"l in order to fix my opinion. 



advantage 



