52 



MR. KATCHKTT'S EXPERIMENTS 



2. Thick brown butyraceous oil, 59; 3. Spongy coal, 13^; 

 4. A fmall portion of carbonate or ammonia, with carbonic 

 acid, carbonated hidrogen, and hidrogen gas, by eflimate 17y.~ 

 Seed lac. Seed lac, by the fame procefs, gave, 1 . Acidulated water, 6; 



2. Thick oil, 61 ; 3. Spongy coal, 7 ; 4. Mixed gas as before, 

 but without ammonia, 26. 



Shell lac. Shell lac gave, 1. Acidulated water, 6; 2. Oil, 65-, 



3. Spongy coal, 7| ; 4. Mixed gas, 24 §. 



The coal of this laft gave one grain of aflies after combuf- 

 tion, which contained a muriate, probably of foda. There 

 was alfo a little iron, and fome particles of fand, probably 

 extraneous. 



Analyfis of Stick Lack. 



Powdered ftick A. 200 grains of flick lac, picked and reduced to powder., 

 lac gave a red wcre diverted in a pint and a half of boiling diftilled water 



colouring extract ° r P 



to water. during 12 hours. The liquor was tranfparent, and of a beau- 



tiful deep red ; this was decanted into another veflel ; and the 

 operation was repeated, with frefh portions of wate., until 

 it ceafed to be tinged ; the lac then appeared of a pale yel- 

 lowifh-brown colour. 



The whole of the aqueous folution being evaporated, left a 

 deep red fubftance, which pofTefied the general properties of 

 vegetable extract, and weighed 18 grains. 



Alcohol then B. The dried lac was digefled for 48 hours, without heat, 



took up much j n e jghteen ounces of alcohol; and the clear tin&ure being 

 cautioufly decanted different portions of alcohol were added, 

 and the digeftion was repeated, until the alcohol ceafed to 

 produce any effect. 



The whole of the foliations in alcohol were then poured into 

 diftilled water, which was heated, and an attempt was made 

 to feparate the precipitated fubftance by filtration ; but, as this 

 did not fucceed, on account of the filter fpeedily becoming 

 clogged, the whole was fubjecled to gentle diftillation ; by 

 which, a brownifh-yellow refin was obtained, amounting in 

 weight'to 136 grains. 



C. The remainder of the lac was again digefied in boiling 

 diftilied water; by which, 2 grains of the colouring extracl 

 were obtained. 



Diluted muriatic D. The rcfiduum was then digefied with one ounce of mu- 



frifSS*^ riatic acid diluted with two ounces of water, which, by boi!- 

 uiaiader. ing, 



