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])

i74 THE, ARTIST'S ASSISTANT.

When the {pint of wine is very firong, it will
tliiiolve a greater proportion of the feed-lac : but this
■will faturate the common, which is felclom of a
ftrength fumcient for making varnifhes in perfec-
tion. As the chillino-, which is the moft incon-
venient accident attending thofe of this kind, is
prevented, or produced more frequently, according
to the ftrength of the fpirit, I will take this oportu-
nity of fhewing a method by which weaker retiified
fpirits may, with great cafe, at any time, be freed
from the phlegm, and rendered of the firft degree of
ftrength.

£: Take a pint of the common reclined fpirit of
" wine ; and put it into a bottle, of which it will not
<; fill above three parts. Add to it half an ounce of

pearl-afhes, fait of tartar, or any other alkaline
" fait, heated red hot, and powdered, as well as it
" can be without much lofs of its heat. Shake the

mixture frequently for the fpace of half an hour ;
t! before which time, a great part of the phlegm will
t; be feparated from the fpirit ; and will appear, to-
" gerher with (he undiffolved part of the laits, in the
"bottom of the bottle. Let the fpirit then be pour-
f: ed off, or freed from the phlegm and falts by

means of atritoriuin, or {eparating funnel ; and let
s: half an ounce of the pearl-afhes, heated and pow-
*; dered as before, be added to it, and the lame treat-
■; ment repeated. Tins may be done a third time, it
" the quantity of phlegm feparated bv the addition of
" the pearl-afhes appear conhderable. An ounce of
1; alum reduced to powder and made hot, but not
i; burnt, muft then be put into the fpirit, and fuffered
'• to remain fome hours ; the bottle being frequentlr
'; faaken. After which, the fpirit being poured off,
fS tt will be fit for ufc.

The