INSECTS. Ill 



by Dr. Roxburgh, — that of a substitute for cochineal ia 

 dying scarlet. The first preparations from it with this 

 view were made in consequence of a hint from Dr. Ban- 

 croft, and large quantities of a substance termed lac-lake, 

 consisting of the colouring matter of stick-lac, precipitated 

 from an alkaline lixivium by alum, were manufactured at 

 Calcutta, and sent to this country, where at first the con» 

 sumption was so considerable that in the three 3'ears previous 

 to 1810 the sales at the India-house equalled in point of col- 

 ouring matter half a million of pounds' weight of cochineal.* 

 "More recently, however, a new preparation of lac-colour, 

 under the name of lac-clie, has been imported from India^ 

 which has been substituted for the lac-lake, and with such 

 advantage that the East India Company are said to have 

 saved in a few months 14,000/. in the purchase of scarlet 

 cloths died with this colour and cochineal conjointly, and 

 ■without any inferiority in the colour obtained."! The only 

 mordant formerly used with kermes was alum, and ths 

 colour communicated was .blood-red ; but Dr. Bancroft as- 

 certained that with the solution of tin used with cochineal 

 it was capable of imparting as brilliant a scarlet as that die> 

 arid one perhaps more permanent. J 



Several other curious and valuable products are obtained 

 from Asiatic insects. The pc-la, or white wax of the Chi- 

 nese, is derived from an insect, probably of the coccus 

 tribe, described by the Abbe Grozier ; and a nondescript 

 Indian species produces a wax analogous to pe-la, first no- 

 ticed by Dr. Anderson under the name of white lac. It 

 may be obtained in any quantity in the vicinity of Madras, 

 and at a much cheaper rate than bees-wax ; but the results 

 of Dr. Pearson's experiments do not countenance the idea 

 that it can be advantageously used for domestic purposes, 

 or at least for the making of candles. i^i Geoffroy had long 

 since attributed to a species of kermes the property of pro- 

 ducing a sugary substance of a white colour, resembling 

 manna ; and Captain Frederick described an article called 



* Bancroft, nlii stipra. 

 ' t Inlrod. to Entom., vol. i. p. 318. 



i It may be mentioned, however, that as ten or twelve pounds of 

 kenTiPs contain no more colouring matter than a single pound of cochi- 

 neal, the latter at its ordinary price is after ail the cheapest. 



$ Philosophical Transactions, 1794. 



