Foreign Vegetables, hi 
them in clofe Veflels •, nor could they be feparated 
from the Earth by any Means, but an open rever- 
beratory Fire, continued for twelve Hours ; where- 
by, at length, they were diflipated in Smoke and 
Flame. 
Moreover, it is worth obferving, that this Coal 
of Guaiacum, being taken out of the Retort and 
expofed to the Air, even two or three Days after 
the Procefs, takes Fire immediately of its own Ac- 
cord •, provided that, when the Diflillation is over, 
the Neck of the Retort be carefully flopped, and 
the VefTels and Furnace be left to cool of them- 
felves. 
The diflilled Oil of Guaiacum is fo greatly con- 
denfated by the Acid in Combination with it, that 
it is eafily converted into an earthy, black, infipid 
Mafs, and becomes entirely fixt. For eight Ounces 
and fix Drachms of the black Oil, being diflilled 
from a Glafs-Retort, gave over feven Ounces, 
two Drachms and a Half of a thinner and more 
fluid Oil, which was fo replete with an acid Spirit, 
that it turned the Tindture of Turnfole to a deep 
red or fiery Colour ; but contained nothing of an 
alkaline Salt, as appeared by its producing no 
Change in the Solution of corrofive Sublimate. In 
the Retort was left a black hard Mafs, of a rare 
Texture, or fpongious like a Pumice-Stone, weigh- 
ing one Ounce, two Drachms, forty eight Grains, 
whereof ten Drachms, being expofed to a very 
flrong Fire in a Crucible, continued flaming for 
two Hours and a Half ; and at lafl, after a Calci- 
nation for four Hours, two Drachms of a denfe, 
hard, infipid, and blackifh Caput mortuum , were left 
in the Crucible. 
The Oil of Guaiacum, when newly diflilled 
and heavy, being mixed with an equal Quantity 
of the redtified Spirit of Nitre, falls immediately 
i into 
