CANADA BALSAM 599 



tained in the Tyrol, Switzerland, and Piedmont, from the 

 common larch, Larix Europaea a lofty tree with graceful 

 drooping branches, and leaves at first in fasciculse, like the 

 pine tribe, but afterwards becoming solitary by elongation 

 of the twigs. Venice turpentine is tenacious, rather opaque, 

 and fluorescent ; less apt than common turpentine to con- 

 crete with keeping ; has a pale yellow colour, an acrid, 

 bitter taste, a disagreeable terebinthinate odour, and con- 

 tains 15 per cent, of oil of turpentine. The Venice turpen- 

 tine of the shops almost invariably consists of about three 

 parts of common resin dissolved in one part of oil of turpen- 

 tine. This artificial mixture is distinguished by its strong 

 odour, and its more quickly evaporating, and leaving a 

 varnish on a sheet of paper, on which the natural Venice 

 turpentine remains viscid. 



CANADA BALSAM, chiefly brought from Lower Canada, is 

 obtained by puncturing the vesicles lying between the bark 

 and wood of Abies balsamea. It is a pale, greenish-yellow 

 oleo-resin of the consistence of thin honey, has an agreeable 

 terebinthinate odour, and a slightly bitter, feebly acrid 

 taste. On exposure it dries slowly into a transparent 

 adhesive varnish, and solidifies when mixed with one-sixth 

 of its weight of magnesia and water. It contains 15 to 

 18 per cent, of oil, is much used by varnish-makers, opticians, 

 and microscopists, and is a constituent, with collodion and 

 castor oil, of flexible collodion. It is sometimes improperly 

 termed Balm of Gilead, which, however, is derived from 

 an Arabian balsamodendron. Strasburg turpentine is a 

 fluid, citron-smelling oleo-resin obtained in the vicinity 

 of the Alps from Abies picea. Chian or Cyprus turpentine, 

 from the island of Scio, nearly resembles Canada balsam 

 in its properties and uses ; it is a greenish-yellow, liquid 

 oleo-resin from the Pistacia terebinthus, a tree of the mastic 

 order. 



FRANKINCENSE, or Thus Americanum, is the semi-opaque, 

 soft, concrete turpentine scraped off the trunks of Pinus 

 palustris, P. Tseda, and other American Coniferae. On keep- 

 ing it becomes dry, brittle, and darker in colour. A similar 

 concrete turpentine comes from the south of France under 

 the name of gallipot or barras. 



