388 Dr. Pearson’s Observations and Experiments 
5. Candles, of different thicknesses, were made of purified 
white lac above mentioned, with cotton wicks of different thick- 
nesses ; and candles were also made of white lac which had been 
dissolved in sulphuric aether, and in volatile oil of turpentine. 
They all burned more rapidly, but I think emitted a less quan- 
tity of light, than wax candles, of the same size. The candles 
made of white lac also smoked and produced a rosinous smell. 
White lac burned in oxygen gaz without affording any 
smoke, and with a beautifully bright flame. 
A small piece of purified white lac, in a platina spoon, was 
exposed to the apex of the violet blue coloured flame of a 
candle, by means of the blow-pipe ; a small quantity of black 
matter remained in the spoon, which could not be carried off 
by a long continued application of the flame ; but after keep- 
ing the spoon red-hot in the fire for ten minutes, nothing but 
a very small quantity of grey ash was left. 
6. From purified white lac nothing could be extracted by 
water ; nor from the lac in its impure state, except a bitterish 
mucilage. 
7. White lac turned to a black coloured substance by boil- 
ing it in concentrated sulphuric acid. The mixture was then 
diluted with water, and by means of the filter a carbonaceous 
matter was separated, which on being made red hot burnt in 
the air without flaming. The filtered liquid, upon evaporation 
to dryness, afforded no alkaline or other residue. 
8. Glass covered with a thin coat of white lac was kept im- 
mersed in oxygenated muriatic acid gaz, and also m water 
saturated with this gaz, for several months, without producing 
any apparent change.on the colour of the lac, or in its other 
properties. 
