LAC 27 



however, become the prey of others, or are carried off by the feet of birds, to which 

 they attach themselves, and are transplanted to other trees. They soon produce 

 small nipple-like incrustations upon the twigs, their bodies being apparently glued, 

 by means of a transparent liquor, which goes on increasing to the end of March, so 

 as to form a cellular texture. At this time the animal resembles a small oval bag, 

 without life, of the size of cochineal. At the commencement, a beautiful red liquor 

 only is perceived, afterwards eggs make their appearance ; and in October or Novem- 

 ber, when the red liquor gets exhaiisted, twenty or thirty young ones bore a hole 

 through the back of their mother, and come forth. The empty cells remain upon the 

 branches. These are composed of the milky juice of the plant, which serves as nourish- 

 ment to the insects, and which is afterwards transformed or elaborated into the red 

 colouring matter that is found mixed with the resin, but in greater quantity in the 

 bodies of the insects, in their eggs, and still more copiously in the red liquor secreted 

 for feeding the young. After the brood escapes, the cells contain much less colouring 

 matter. On this account, the branches should be broken off before this happens, and 

 dried in the sun. In the East Indies this operation is performed twice in the year ; 

 the first time in March, the second in October. The twigs encrusted with the radiated 

 cellular substance constitute the stick-lac of commerce. It is of a red colour more or 

 less deep, nearly transparent, and hard, with a brilliant conchoidal fracture. Tho 

 stick-lac of Siam is the best ; it often forms an incrustation fully one quarter of an 

 inch thick all round the twig. The stick -lac of Assam ranks next ; and, last, that of 

 Bengal, in which the resinous coat is scanty, thin, and irregular. There are three 

 kinds of lac in commerce : stick-lac, which is the substance in its natural state, seed- 

 lac, and shell-lac. According to the analysis of Dr. John, stick -lac consists of- 



An odorous common resin ....... SO'OO 



A resin insoluble in ether 20-00 



Colouring matter analogous to that of cochineal . . . 4'50 



Bitter balsamic matter ....... S'OO 



Dun yellow extract ........ 0'60 



Acid of the stick-lac (laccic acid) . 075 



" Fatty matter, like wax 3-00 



Skins of the insects, and colouring matter .... 2-50 



Salts 1-25 



Earths 075 



Loss 475 



120-00 



According to Franke, the constituents of stick-lac, are, resin, 657 ; substance of 

 the lac, 28'3 ; colouring matter 0-6. 



Seed-lac. When the resinous concretion is taken off the twigs, coarsely pounded, 

 and triturated with water in a mortar, the greater part of the colouring matter is dis- 

 solved, and the granular portion which remains being dried in the sun, constitutes 

 seed-lac. It contains of course less colouring matter than the stick-lac, and is much 

 less soluble. Mr. Hatchett's analysis of seed-lac was as follows : 



Eesin . 68 



Colouring matter 10 



Wax . 7 



Gluten. . 5'5 



Foreign bodies 6'5 



Loss 4 



100 



John found in 100 parts of it, resin, 667 ; wax, 17 ; matter of the lac, 167 ; bitter 

 balsamic matter, 2'5 ; colouring matter, 3'9 ; dun yellow extract, 0-4 ; envelopes of 

 insects, 2'1 ; laccic acid, O'O ; salts of potash and lime, TO; earths, 6'6 ; loss, 4-2. 



Shell-lac. In India the seed-lac is put into oblong bags of cotton cloth, which are 

 held over a charcoal fire by a man at each end, as soon as it begins to melt, the 

 bag is twisted so as to strain the liquefied resin through its substance, and, to make 

 it drop upon smooth stems of the banyan-tree (Musa paradisa). In this way, the 

 resin spreads into thin plates, and constitutes the substance known in commerce by 

 the name of shell-lac. 



The Pegu stick-lac, being very dark coloured, furnishes a shell-lac of a correspond- 



