Translation of Rey's Essaj/s. 281 



such manner that the true fixed salt exists in the volatile salt, 

 as well as another less earthy of a sulphureous nature, and a 

 third, greatly subtile and penetrating, partaking of the nature of 

 mercury. Now crude and cold mercury readily penetrates 

 through gold, and attaches itself closely to it within and with- 

 out ; so that it is not unreasonable to imagine, that the volatile 

 salt of a mercurial nature, rarefied by and rendered much more 

 penetrating by fire, should pass through the substance of the 

 vessels, which are in like manner heated and rendered more 

 penetrable by the fire, and should attach itself to the calx of tin, 

 by a certain sympathy that may exist between them, as well as be- 

 tween gold and crude mercury. This second opinion is sufficiently 

 overturned by the reasoning in the preceding essay ; for having 

 shewn that there can be no volatile salt in charcoal, who but must 

 see that it cannot exist in any manner whatever ? On the other 

 hand, if this mercurial salt penetrated the vessels, it would neces- 

 sarily dissolve them and make an amalgam with them, which by 

 no means happens in our calcination. Besides, since crude mer- 

 cury exhales, as we see, at a very low heat, hovi' can it happen 

 that this mercurial salt, being of so subtile a nature, after it has 

 penetrated the vessel, should remain in the burning calx, with- 

 out quickly flying off ? Moreover, if wc are to find in each of 

 the principles all the three, I do not see why each of these agaia 

 should not contain them all, and so on ad infinitum. These 

 speculations are manifestly subtile, but have no foundation in 

 nature. 



ESSAY XXIV. 



/* is not moisture attracted by the calx that increases its weight. 

 Conversing, not long since, with a learned man of good judg- 

 ment, I took the opportunity of mentioning this subject to him, 

 on which, not having thought at all on the matter, he told me, 

 that he believed that the calx, by its great dryness, attracts much 

 moisture, and that it is this which increases its weight. I can- 

 not approve of this opinion, for the following reasons : First, 

 because I have never learnt that a contrary attracts its con- 

 trary; it rather flies from it, or drives it away if it can. Be- 



