198 Mr. Hatchett's analytical Experiments 
and nearly white. I at first therefore suspected, that some 
caoutchouc was present in lac ; but, finding that boiling water 
destroyed this elasticity, I was induced to make subsequent ex- 
periments, by which I discovered, that the elasticity of this 
residuum, was principally owing to a substance which appeared 
to possess the properties of vegetable gluten. This, however, I 
shall more fully notice in another part of the Paper. 
The resin obtained from the varieties of lac is brownish yel- 
low, and is not so brittle as the generality of other resinous 
substances. 
3. Sulphuric ether does not seem to act so powerfully upon 
the varieties of lac as alcohol ; for, as a great part of the resin 
is protected by the colouring matter, and by the other ingredients 
which are insoluble in ether, it naturally follows, that less of it 
can be separated by this liquid than by alcohol. 
The different kinds of lac which have been digested in ether 
are considerably softened, although in other respects very little al- 
teration is produced. Ether, therefore* is not the best menstruum 
for lac ; but, under certain circumstances, it may be occasionally 
employed with advantage, for the purpose of analysis. 
4. Concentrated sulphuric acid acts in the first instance on 
the colouring matter of lac; but, after a short digestion in a 
sand-bath, the whole is converted into a reddish-brown thick 
liquor, which soon becomes black ; and the chief part of the lac 
is separated, in an insoluble state, resembling coal. 
During the solution of lac in sulphuric acid, a considerable 
quantity of sulphureous acid gas is evolved. 
5. When lac is digested with nitric acid, nitrous gas is at 
first produced; the lac swells much, and is converted into 
