I 3 6 THE HISTORY OF CHEMISTRY, 



ger, a fmall particle of the ftonc, which he af- 

 terwards threw into ibmc melted lead; but the 

 whole almofl evaporated, leaving behind only 

 a kind of vitreous earth. On his relating this 

 difappointment, the alchcmiil candidly acknow- 

 ledged the deceit ; but direded him in future 

 to inclofe the (lone in wax, that it might not 

 be aHeclcd by the fumes of the lead. He in- 

 flrucled him in other circumftanccs likewiie ; 

 told him that the whole proccis could be com- 

 pleated in a few days, and that two florins would 

 defray all the ex pence. In order, however, to 

 teach him the method of performing the ope- 

 ration, he promiied to be with him again the 

 next day. The appointed hour came, but no 

 flranger; and Hclvetius having waited for him 

 with fome impatience, but to no purpofe, re- 

 folved on making the experiment in preicnce of 

 his wife and his fon. To fix drachms, of lead 

 melted in a crucible, he added the piece of 

 Aone he had received the day before, wrapped 

 up in yellow \v^x ; then covering the crucible, 

 he left it for a quarter of an hour cxpoicd to the 

 re ; at the expiration of which he found the 

 whole mufs converted into gold. At firlt, it ap- 

 peared of a gu-enifh colour; but being poured 

 out into a vcilcl of a conical fhapc, it a Homed a 

 tinge like blood, and afterwards, as it grew cold, 

 the true golden hue. This gold was examined 

 by a ftoldlmilh, who found it fovery pure, th:*t 



