and Observations on Lac. 
20 * 
an average, requisite to dissolve too grs. of shell lac ; but more 
water may be occasionally added, to supply the loss caused by 
evaporation during the digestion, which should be made nearly 
in a boiling heat. 
This solution of shell lac is turbid, and of a reddish-bfown 
colour; when considerably diluted with water and agitated, a 
weak lather is formed ; it is decomposed by acids, and the lac is 
precipitated in yellow flocculi, which do not apparently differ 
from the lac originally employed. 
The general properties of the solution show, that it is a sa- 
ponaceous compound, which, being used as a varnish or vehicle 
for colours, becomes (when dry) difficultly soluble in water, 
although this was the liquid employed to form the solution. 
A white thick scum or cream collects on the surface of this 
liquid, after it has been suffered to remain tranquil for some 
time, and is found to be produced by a sort of wax, which I 
shall more particularly notice when the analyses of the varieties 
of lac are described ; but, in the present case, this wax appeared 
in some degree to be converted into an almost insoluble soap by 
the alkali of the borax, and may be regarded as the principal 
cause of the turbidness of the solution. 
l i. The lixivia of pure soda and of carbonate of soda com- 
pletely dissolve the different kinds of lac ; and these solutions 
exactly resemble those formed by means of borax, excepting 
that they are deeper coloured. 
Rather less than ± of carbonate of soda is required to dissolve 
shell lac; and this solution, when dried, is sooner affected by 
damp or water than the solution prepared by borax. 
12. Lixivium of pure or caustic potash speedily dissolves the 
Dd 2 
