that which is adulterated; You may easily discover the Oyl of
Turpentine, by setting it on fire, for it yields abundance of
ill-scented smoak, with very little savour of the Herb, Flour, or
Seed, &c. and soon takes fire. To correct the ill smell of the
Turpentine, they digest it with, and distil it off with Spirit of
Wine. Those sophisticated with Turpentine, fired in a Silver Spoon
colour it, and quickly diffuse themselves upon a Knife, or Paper. The
best way to try by firing, is to put a drop or two of these Oyls on
the end of a broad pointed Knife, which being first heated, and then
thrust into a lighted Candle, presently take fire, and break out into
a flame with much dark smoak; but if you will try them in a Spoon,
heat it first over a Candle, and then blow the flame of lighted paper,
or of a Wax Candle on them. To try the scent, blow out the flame of
the good Oyls, and your smell will soon discover the ill scent of the
Turpentine from that of the good Oyl. But on the contrary, all Oyls
drawn from Plants by distillation hardly flame, and the flame soon
goes out, and the smoak gives a full flavour of the Plant it self,
whereas those sophisticated as before, differ from the true in both.
The same Oyls are also sophisticated with cheap ones drawn from
decayed Oringes, and Limons; Your smell on firing will soon discover
these mixtures. A third way of sophisticating Chymical Oyls is, by
mixing with them such Oyls as are made by expression, which are easily
discovered by rubbing them on white paper, which being held and dryed
at the fire, the Chymical part soon flyes away, and leaves the paper
transparent, looking no otherwise then oyled paper; but pure Chymical
Oyls totally fly away, leaving the paper white as 'twas before, and
not transparent, and in this way Oyl of sweet Almonds and Spike have a
great share. As for Oyls drawn by Retort, they all of them smell so
strong of the fire, that neither smell nor tast can well discover any
fraud in them. Now for the fixed Salts, most of them are made of the