on a Wax-like Substance from Madras. 389 
9. On about 100 grains of white lac were poured 400 grains 
of concentrated nitrous acid. In a few minutes time the 
acid became of a deep orange colour, and, on making it hot, 
nitrous gaz was discharged, with an ebullition of the liquid. A 
fresh discharge of nitrous gaz took place on adding more ni- 
trous acid. On applying caloric, to make the acid boil and to 
melt the lac, this substance was totally dissolved ; but on 
standing to cool, it seemed to be wholly separated from the 
acid, and was rendered white. On diluting with water the 
acid from which the lac had separated itself, a very slight 
curdy precipitation took place ; and the same appearance took 
place on adding ley of pot-ash. On evaporating this acid to 
dryness, a very small residue of lac was obtained. I dissolved 
a little of this substance by boiling it in concentrated nitrous 
acid, and poured the solution, while hot, into water ; upon 
which a very copious precipitation instantly took place, of the 
lac rendered quite white. 
10. One hundred grains of the substance under examination 
were totally dissolved, and very readily, in 500 grains of vola- 
tile oil of turpentine. While this solution was hot it was clear, 
but on cooling it grew opaque and white. On evaporation 
the whole of the lac was recovered. 
11. Fifty grains of white lac readily dissolved in 500 grains 
measure of sulphuric aether, in the temperature of 8o°. This 
solution was not unctuous, or resinous ; the lower part of 
it was like an emulsion, and the upper part was transparent 
and limpid; but both parts contained the substance dissolved. 
Upon evaporation the lac was recovered in the form of alight 
white powder, which on melting became a brittle yellow solid, 
as heavy as before solution. 
