438 COMPOUND PRODUCTS. CHAP. I. 



America. It resembles copal exactly in its appear- 

 ance ; but differs from it in being readily soluble 

 in alcohol. It is employed also in making var- 

 nishes. 



Lac. This resin is the produce of the Croton 

 facciferum, a native of the East Indies. It exudes 

 in consequence of the puncture of an insect, whence 

 it is supposed to derive its colour, which is deep red 

 verging on brown, with a degree of semi-trans, 

 parency. It forms the basis of many varnishes, 

 and of the finest kinds of sealing-wax. 



Bloom. -Upon the epidermis of the leaves and 

 fruit of certain species of plants, there is to be 

 found a fine soft and glaucous powder. It is par- 

 ticularly observable upon cabbage leaves, and upon 

 plums, to which it communicates a peculiar shade. 

 It is known to gardeners by the name of bloom. 

 It is easily rubbed off by the fingers ; and when 

 viewed under the microscope seems to be composed 

 of small opaque and unpolished granules, some- 

 what similar to the powder of starch ; but with a 

 high magnifying power it appears transparent. 

 When rubbed off it is again reproduced, though 

 slowly. It resists the action of dews and rains, and 

 is consequently insoluble in water. But it is soluble 

 in spirits of wine ; from which circumstance it 

 has been suspected, with some probability, to be a 



resin.* 



Mirbel, Phy?. Vcg, vol. i. p. 1 12. 



