... [ 853 ] 
thing in that gentleman’s elaborate treatife on anti- 
mony. 
As the fulphur auratuin is now very frequently 
ufed in medicine, moie exadtnefs feems required in 
its preparation than is commonly pradtifed : for cer- 
tainly the firft precipitation differs not a little from 
the fubfequent, as being of a darker colour, and 
greater fpecific gravity, and of courfe more regu- 
line. ’Tis alfo of fome confequence how long the 
flibiate lixivium ftands before the acid is poured on ; 
for by time it will of itfelf drop much of the ful- 
phureo-reguline fubftance ; efpecially if it is kept in 
an atmofphere much impregnated with the fumes of 
vinegar, fulphur, or the like ; and, in fuch cafe, the 
fucceeding precipitate, with an acid, will be much 
milder, as being lefs metallic, but more filphu- 
reous. The quantity and quality of the precipi- 
tating acid are alfo of confequence. Vinegar may 
rather augment the emetic power ; and fpirit of fait, 
or vitriol, may make a precipitate not altogether fo 
proper to mix with calomel, as in Dr. Plummer’s 
alterative pill, &c. Great care fhould be taken there- 
fore in the ablution of the fulphur auratum; for the 
acid falts are not fo eafily wafhed off as fome 
would imagine, and it cannot be doubted but that 
fome of them fall with the precipitate. Who 
would think fuch a quantity of falts lay hid in the 
calx of filver, precipitated out of a folution of it in 
aqua fortis, by fea fait, which though perfe&ly 
wafhed, and altogether infipid (as is the luna cornea,, 
into which it readily melts) yet two parts of this, 
intimately mixed with one part of regulus of anti- 
mony, and diftilled, give a mod cauftic kind of but- 
ter 
