The Artist's Assistant, In the Study and Practice of Mechanical Sciences: Calculated for the Improvement of Genius. Illustrated with Copper-Plates — Birmingham, [ca. 1785]

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1 cm

plex by ingredients not effential to the-intention, or
too coftly by the ufe of fuch as are expenfive; or
inferior in goodnefs, from the improper choice or
proportion ol the component fubflances.

The principal body or matter of all good lacquers
ufed at prefent is feed-lac ; but, for coarfer ufes,
refin, or turpentine, is added, in order to make
the lacquer cheaper than if the feed-lac, which is a
much dearer article, be ufed alone. Spirit of wine
is alfo confequently the fluid or menftruum of which
lacquers is formed ; as the ethereal oils will not dif-
folve the feed-lac, and it is proper that the fpirit
fnould be highly rectified for this purpofe. As it is ^
feldom practicable, neverthelefs, to procure fuch
fpirils from the fhops, it will be found very advan-
tageous to ufe the method above given for de-
phlegmating it by alkaline falts ; but the ufe of the
alum, directed in that procefs, muft not be forgotten
on this occafion ; as the effect of the alkaline fait
would otherwife be the turning the metel of a pur-
plifh inftead of a golden colour, bv laying on the

The following are excellent compofitions for brafs
work which is to refemble gilding :

w Take of turmeric ground, as it may be had at
<: the dry-falters, one ounce, and of faffron and Spa-
" nifh annatto each two drams. Put them into a
': proper bottle, with a pint of highly rectified fpirit
': of wine ; and place them in a moderate heat, if
" convenient, often fhaking them for feveral days.
" A very ftrong yellow tincture will then be obtain-
'; eel, which muft be (trained off from the dress
" through a coarfe linen cloth ; and then, being put
c; back into the bottle, three ounces of good feed-

" lac.
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