94 



PHILOSOPHICAL TKANSACTIONS. 



[anno 1736. 



distillation, the whole of the mercury passed over into the receiver in the form 

 of fluid quicksilver, without leaving any residuum in the retort. Hence (says 

 Dr. B.) it is evident, that quicksilver is not fixable by long continued exposure 

 to the degree of heat beforementioned. 



But lest it should be objected that the access of the air prevented its fixation. 

 Dr. B. subjected a quantity of purified quicksilver to lOO degrees of heat for 

 4. year (viz. from Dec. 173'i to July 1733), in close vessels. He afterwards 

 subjected a quantity of this quicksilver to the heat of a sand-bath, nearly equal 

 to the heat of boiling water, in vessels well closed. The quicksilver was found 

 to be unaltered, excepting a very small quantity of black powder on its surface, 

 which, as in the former instance, was revived by trituration. Being subjected 

 to distillation, the whole of the quicksilver passed over into the receiver, leav- 

 ing no residuum in the retort. The futility therefore of attempting to fix 

 quicksilver is clearly proved. 



But it had been asserted by some chemical authors and particularly by Van 

 Helmont, that some metals were resolvable into quicksilver. " When lead 

 (says the last mentioned chemist) is dissolved by alkalies and salts, or oil, 

 which take in the sulphur and separate it from the body, the lead by this means 

 becomes changed into a volatile running mercury, which can no more endure 

 the fire, as before, but is cold and running like water, and without a metalline 

 form." (Vide Paradoxical Discourses of V. Helmont, Lond, l685. Part II. 

 § 22.) The same thing is affirmed by Joachin Becher. (Vide Collectanea 

 Quingentor. Experimentorum k p. 310, ad p. 333.) But after subjecting lead 

 to processes similar to those described by the last mentioned authors, as well as 

 to a treatment similar to that described by Isaac Hollandus ; Dr. B. was unabls 

 to extract a single particle of quicksilver from that metal. 

 ^ Dr. B. afterwards made a numerous and laborious set of experiments on 

 amalgams of lead and quicksilver, of tin and quicksilver, and lastly of gold 

 and quicksilver. After long-continued* digestion in a heat of 84, the amal- 

 gam of lead being distilled, the quicksilver passed over into the receiver, minus 

 43 grs. in 3 oz. (the total quantity of quicksilver operated upon in this expe- 

 riment) in part accounted for by the red powder (precipitate per se) which re- 

 mained behind in the retort, which was not volatile in the aforesaid degree of 

 heat. The weight of the lead was found to be the same as before the opera- 

 tion, viz. 1 oz. Hence it appears that no mercury is obtainable from lead-|- by 

 amalgamation, digestion and distillation with quicksilver, in the manner above- 

 mentioned. 



* From the 1 1th of Feb. 1732, to the 10th of Jan. 1735. 

 f In other words, none of the lead is convertible into mercury. 



