VOL. X.] PHILOSOPHICAL TRANSACTIONS. 26q 



durable) I found by trial that a single drachm of mercury, made after a certain 

 manner, did the third or fourth year after I had laid it by, grow so hot with gold, 

 that I feared it would have burnt my hand. 



I shall therefore admonish those inquisitive spagyrists, that may be desirous 

 to try, whether their purified mercury be incalescent, that they be not too hasty 

 to conclude it is not so ; nor to reject it, unless they have made the trial with 

 gold duly prepared. For I have found, that my mercury did not grow hot with 

 the smallest filings of gold I could make (though indeed within a few hours after 

 it did, without the help of fire, embody with it into a hard amalgama,) which 

 argued that the corpuscles of the metal were not yet small enough to be sud- 

 denly penetrated by the quicksilver : nor will every calx of gold serve our turn, 

 as I have found by employing, without success, a very fine and spongy calx 

 made after an uncommon way, the golden particles having, as it seemed, some 

 extremely fine though unobserved dust of the additament sticking to them, 

 which hindered the adhesion of the mercurial ones. Now the calx of gold that 

 I most used, as finding it still to do well, was that made by quartation* (as 

 Alchymists call it.) But because it is not so easy, as even chemists that have 

 not tried imagine, to make good calces of gold, and that in the way newly 

 mentioned there needs fusion of the gold and of silver (for which many chemists 

 want conveniences,) and they are often imposed on by common refiners, who 

 here usually sell in wires such silver for fine (which indeed it is comparatively,) 

 as I have found not to be without mixture ; I shall add, that by making an 

 amalgama the common way with pure gold and vulgar mercury, and dissolving 

 the mercury in good aquafortis, there will remain a powder, which, being well 

 washed with fair water to dulcify it, and kept a while in a moderate fire to dry 

 thoroughly without melting it, will become a calx, which I have more than 

 once used with our mercury with good success. It is true, both in this way and 

 in that (by quartation,) aquafortis, which is a corrosive liquor, is employed to 

 bring the gold to powder, and therefore in a diffident mind some suspicion may 

 arise, that the incalescence may proceed only from the action of the acid parti- 

 cles of the menstruum, which yet adhering to the corpuscles of the gold works 

 upon the quicksilver, as aquafortis is known to do : but, to omit those answers 

 that cannot be given in few words, after I have taken notice, that, if the effect 

 depends not on our mercury (as prepared) but only on the calx, it appears not, 

 why this should not grow hot with common mercury as well as with ours ; I 



■* That is, by melting togetlier one part of fine gold, and three or four parts of cuppelled silver, 

 and then putting the mass, wherein the metals are mixed, almost per minima, into purified aqua- 

 fortis, which dissolving the silver only, leaves the gold in the form of a fine calx. — Orig. [The terra 

 calx of gold is here improperly used] for in the operation of parting with aquafortis, the gold is left in 

 its reguline state.] 



