[ 5 ] 
too fierce at the Beginning, or ufing the Oil of 
Vitriol too weak : But fuch a Sublimation of the 
Sulphur is no farther Detriment to the Operation. 
V. VVhen Lime is ufed in this Procefs, a confidera- 
b!e Proportion of fixed Alkali Salt may be faved, 
the Spirit be rendered ftronger, and the Caput 
mortuum cleaner and whiter, fo as to make an 
excellent Tartar of Vitriol, by Solution, Filtration, 
and Cryftallization : But it muff be obferved, That 
the Produce of this Tartar of Vitriol, when pre- 
pared, is not near fo large as when no Lime has 
been ufed in it; and accordingly I have found, that 
-the dry Powder, remaining after the Solution and 
Evaporation of the Sal Alkali and Sulphur alone, 
weighs as much as they did originally : Whereas, 
when Lime has been ufed, the remaining Powder 
has weighed half a Pound lcfs than the original 
Weight of the Sulphur and fixed Salt ; which feems 
a curious Phenomenon ; and might lead to farther 
Difcoveries of the Relation betwixt Lime and 
fixed Alkali Salt, <&c. 
VI. The Advantages of this Method, in refped of 
M. Hombergs , are, 
(i.) That it gives a much larger Quantity of the 
Acid of Sulphur. (2.) That it gives a very vo- 
latile Acid i whereas his is fixed, fo as fcarce to 
differ from Oil of Vitriol. (3.) That it is ob- 
tained in a much more eaCy and cheap Manner. 
(4.) That this Spirit has, probably, much greater 
medicinal Virtues. (5.) That it is a much more 
powerful Menftruum ; efpecially with regard to 
Metals, and particularly their Cryftallization. 
(< 5 .) That the Caput mortuum is a Medicine of 
great 
