on a Wax-like Substance from Madras. 387 
It was yellow like bees wax ; hard and brittle as rosin. It had 
no bitterish or scarcely any other taste. It melted in alcohol, 
and also in water, of the temperature of between 145 0 and 146°. 
Purified white lac adheres very firmly to wood, tin, paper, 
&c. so that it is an excellent cement on many occasions. 
hi. Experiments - to discover some of the Affinities and Combi- 
nations of white Lac. 
1. Yellow purified lac above mentioned was spread thin 
upon a plate of glass, and exposed to the rays of the sun during 
the whole of the month of July, 1793, but it was not by this 
means rendered at all less yellow. 
2. A bit of white lac, on boiling in water with powdered 
charcoal, was absorbed, and disappeared. 
3. Purified lac was digested in various proportions of ley 
of pure pot-ash, in different temperatures, but an uniform or 
soap-like mass could not be formed. The mixture emitted 
the smell of palm oil. The lac turned to a brown colour, and 
had the appearance of a coagulated mass, in the liquid as well 
as dry state. The liquid filtered from these solutions had a 
sweetish and bitterish taste. Upon the addition of vinegar, it 
became very turbid and rose-coloured ; and by standing it 
let fall a copious sediment, which being dried was found to be 
white lac only rendered more brittle. 
4. Ammoniac , or caustic volatile alkali seemed to combine 
with the white lac. The compound was a tolerably uniform 
brown soapy substance. It tasted sweet, and had still a weak 
smell of ammoniac. It rendered water milky, and this solu- 
tion became curdy on adding to it acetous acid. 
3D 2 
