Experimerits and Observations on Lac. 13 



The coal of the shell lac, by incineration, afforded about 

 otie grain of ashes, which contained a muriate, probably 

 of soda, and a little iron, with some particles of sand, 

 which may be regarded as extraneous. 



Anabjsis of Slick Lac. 



A. 200 grains of stick lac, ii)icked and reduced to powder, 

 were digested in a pint and a half of boiling distilled water 

 during 12 hours. 'J'he liquor was transparent, and of a 

 beautiful deep red ; this was decanted into another vessel, 

 and the operation was repeated, with fresh portions of wa- 

 ter, until it ceased to be tinged ; the lac then appeared of a 

 pale yellowish-brown colour. 



The whole of the aqueous solution being evaporated, left 

 a deep red substance, which possessed the general proper- 

 ties of vegetable extract, and weighed 18 grains. 



B. The dried lac was digested for 48 hours, without heat, 

 in eighteen ounces of alcohol ; and the clear tincture being 

 cautiously decanted, different portions of alcohol were 

 added, and the digestion was repeated, until the alcohol 

 ceased to produce any effect. 



The whole of the solutions in alcohol were then poured 

 into di^-tilled water, which was heated, and an attempt was 

 made to separate the precipitated substance bv filtration ; 

 but, as this did not succeed, on accoimt of the filter 

 speedily becoming clogged, the whole was subjected to 

 gentle distillation ; bv which a brownish-yellow resin was 

 obtained, amounting in weight to 136 grains. 



C. The remainder of the lac was again digested in boil- 

 ing distilled water ; by which 2 grains of the colouring ex- 

 tract were oblained. 



D. The residuum was then digested with one ounce of 

 muriatic acid diluted with two ounces of water, which, by 

 boiling, became of a britrht pale red, but changed to purple, 

 when saturated with a sokition of carbonate of potash. 



A flocculcnt precipitate was thus bbtaincd, which pos- 

 sessed the characters of precipitated vegetable gluten couj- 

 bined with some of the colouring extract 3 this, whencom' 

 plctely dried, weighed 11 grains. 



E. There now remained 25 grains, which evidently con- 

 sisted of a sort of wax, mixed with sniall parts of twigs 

 and other extraneous sub?tances. 



A part of the wax was separated by heat and pressure in a 

 piece of linen ; and anolhc-r portion \ /as separated by di- 

 gestion in olirc oil, whi-.'h assumed the consistency of an 

 unguent. 



The 



