76 MICA AND ITS USES. 



tax, would be little felt in an article the consumption of which falls upon 

 no particular class, while the revenue derived from this source might be 

 devoted to the construction of roads ; and thus, by facilitating transit, ulti- 

 mately cause a reduction in tbe price of the article, more than equivalent 

 to the duty levied upon it. 



One of the principal uses to which mica is turned on the other side of 

 India is as a substance for miniature drawing and paintings, for which Delhi 

 and other towns in the north-west have long been remarkable. The manu- 

 facture of ornaments from it for female attire is carried on on a very exten- 

 sive scale in the Bombay bazaar : we are not aware that any account of it 

 has appeared in print. The mica which is most firm, elastic, and trans- 

 parent, chiefly found in soft, flexible, and silvery varieties, fetches a com- 

 paratively trifling price. It is split into thin plates, which are set aside for 

 use. When meant to be coloured, a piece of white or yellow foil, either 

 plain or coloured, in general either crimson or green, is placed between a 

 couple of plates of mica, which are firmly gummed together. A thin sheet 

 of tin, brass, Dutch gold, or plaited copper, is now taken and punched out 

 in little capsules about the size of half a sweet pea, or half a pellet of No. 1 

 shot. These are carefully lifted and gummed in regular patterns on the 

 mica, which is then cut into small discs, generally circular, or of the form 

 of a star. These are fastened on paper and sold for so much a dozen. They 

 are afterwards neatly stitched all over the thin muslin parts of the 

 dress, in such a manner that the effect produced by them is extremely 

 pleasing. 



In Siberia thin sheets of mica have long been used for glazing windows, 

 whence it has been called Muscovy glass. It is found in Siberia and on 

 the borders of the Caspian Sea, in very large sheets of three or four feet 

 square. It is regularly quarried, and forms an article of commerce, the 

 price varying according to the purity and size of the plates. Very large 

 plates are dear ; those of ordinary size sold some few years ago at 5s. or 6s. 

 each on the spot. Brown and grey mica are used in lanterns, in stove 

 doors, and in the windows of some ships of war ; bearing change of tem- 

 perature better than glass, and not being subject to break with the percus- 

 sion occasioned by the discharges of cannon. 



Mica is sometimes employed in the making of false avanturine, and for 

 other similar purposes, when it is required to produce the appearance of a 

 gold and silver powder. Walls are sometimes powdered over with mica, 

 which gives them a pretty brilliant appearance. It is also employed as a 

 sand to dry writing, for which purpose it is sometimes coloured. In th e 

 state of a very fine powder it is known as cat's gold and cat's silver. 



Mica is easily separable into very thin plates, about the 250,000th part of 

 an inch in thickness, and is in that state almost transparent ; hence it is 

 useful in optical experiments. 



Lepidolite is a variety of mica, containing lithia and fluoric acid. It is mas- 

 sive, but composed of brilliant and pearly spangles, or little lamillar masses 

 of a pretty lilac colour, and sometimes pearl blossom, of a very charming 



