of the Acid of Borax. 63 
ounce and three drams of the muriatic acid, in addition, and 
allowed the mixture to digest gently for some days. 
Exp. xvi. In this twelfth distillation, there appeared a large 
quantity of flocculent sublimate, looking almost like branches, 
hanging down, and in many places of a yellow colour ; it ex- 
tended even into the neck of the retort, and almost covered 
the interior aperture of the tube. 
Exp. xvii. The thirteenth distillation produced the same 
phasnomena. Upon the lowermost surface of the mass of salt, 
many light-brown spots appeared, as soon as the fluid was so 
much evaporated that no more of it could be seen upon the 
salt. 
From all these circumstances, I now believed the mass of 
salt, by a digestion of twenty-two days, and seven distillations, 
from Exp. xi. to xvii. (that is, by a digestion of fifty-four 
days, and thirteen distillations, in the whole,) to be so far de- 
composed, as to admit of a separation of some of its constituent 
parts. I therefore supposed I might leave off applying only a 
digestive warmth, and proceed to a greater degree of heat. 
Exp. xviii. Having poured out the fluid obtained by Exp . 
xvii. and replaced the phial, I increased the degree of heat. By 
this, the retort became quite obscured, first by fumes, and after- 
wards by a quantity of white sublimate, attaching itself to all 
its sides, which, however, had not the appearance of common 
sedative salt. As I increased the heat, the sublimate grew 
darker in colour; afterwards became black and frothy; and, at 
length, ran down the sides of the retort, in different places, like 
thick oil of hartshorn, the retort being almost wholly blackened 
by it. 
Exp. xix. While the retort was still warm, I poured into it 
