i 9 6 
Mr. Hatchett's analytical Experiments 
§ 1 . 
EFFECTS OF DIFFERENT MENSTRUA ON THE VARIETIES OF LAC. 
1. When water is poured on stick lac, which has been sepa- 
rated from the vegetable branches, and reduced to a coarse 
powder, it immediately begins to be tinged with red; and, with 
the assistance of heat, a deep coloured crimson solution is 
formed. 
Repeated operations of this kind reduce stick lac to a yellowish- 
brown substance ; and the water no longer receives any colour. 
The portion thus separated from stick lac has, upon an 
average, amounted in my experiments to about 10 per cent, but 
this is not to be regarded as the total quantity, for a part is ob- 
stinately retained Ty the resin and other ingredients, so that it 
cannot be completely separated ; and moreover, very consi- 
derable variations must be expected in different samples. 
Fine seed lac did not afford more than zj- or 3 per cent. 
of the colouring substance; and shell lac, when treated in the 
same manner, (i. e. merely with water,) did not yield more 
than \ per cent. 
2. Alcohol dissolves a considerable portion of each of the 
different kinds of lac; and, when heat is not employed, the dis- 
solved part is resin, combined with some of the colouring matter; 
but, if the lac is digested with heated alcohol, then the solution 
is more or less turbid, in consequence of some of the other in- 
gredients becoming mixed and suspended; so that it is afterwards 
extremely difficult to obtain it in a state of purity and trans- 
parency, either by repose or by filtration. 
The resin may be obtained by immediately subjecting the 
