I 
Painting. 
Mr. kerr’s Hijlory of the 
ing grindftones are made only of fuch fand as will 
pafs eafily through fine muflin, in the proportion 
of two parts fand to one of Lac. This fand is 
found at Ragimaul. It is compofed of fmall an- 
gular cryftalline particles, tinged red with iron, 
two parts to one of black magnetic fand. 
The ftone-cutters, inftead of fand, ufe the 
powder of a very hard granite called Corune. 
Thefe grindflones cut very faft. When they 
want to increafe their power they throw fand 
upon them, or let them occafionally touch the 
edge of a vitrified brick. The fame compolition 
is formed upon flicks, for cutting flones, fhells, 
&c. by the hand. 
Take one gallon of the red liquid from the firfl 
wafliing for Shell Lac, {train it through a cloth, 
and let it boil for a fhort time, then add half an 
ounce of foap earth (foffil alkali) ; boil an hour 
more, and add three ounces of powdered load 
(bark of a tree) ; boil a fhort time, let it Hand 
all night, and ftrain next day. Evaporate three 
quarts of milk, without cream, to two quarts, 
upon a flow fire, curdle it with four milk, and 
let it Hand for a day or two ; then mix it with 
the red liquid above mentioned ; ftrain them 
through a cloth, add to the mixture one ounce 
and an half of allum, and the juice of eight or 
ten lemons : mix the whole, and throw it into a 
cloth-bag ftraiiier. The blood of the infedt forms 
a coagulum with the cafeous part of the milk, 
and remains in the bag, while a limpid acid 
• water 
