POPLAR BUDS 157 



A number of methods are employed in the production of Charcoal as 

 the use of heaps, iron cylinders or overheated steam. The yield of 

 Charcoal varies from 15 to 25 per cent and that made from the willow 

 is preferred. Maple charcoal is also largely employed. 



Charcoal retains the shape of the pieces of wood from which 

 it is formed. It is black, inodorous, tasteless, very porous, brittle 

 and insoluble in any of the ordinary solvents. In medicine it is 

 usually used in the powdered form and when examined by means of 

 the microscope it is seen to consist for the most part of purplish- 

 black irregular structureless fragments. It consists largely of pure 

 carbon, retaining the ash of the wood from which it was derived. 

 Upon heating a small quantity of charcoal with alcohol and filtering, 

 the filtrate should leave no residue upon evaporation. If 1 gm. of 

 charcoal is boiled with 5 c.c. of a solution of one of the alkalies and 

 filtered, the filtrate should be colorless (evidence of complete carbon- 

 ization). The soluble ash in charcoal may be extracted by means of 

 dilute hydrochloric acid. 



A fine charcoal is made from the wood of the Linden and Poplar 

 in Europe; and under the name of Carbo Panis a charcoal is made 

 from bread. 



GEMMAE POPULI. Turiones Populi, Balsam Poplar Buds or 

 Balm of Gilead Buds. The buds of the balsam poplar or Taca- 

 mahac (Populus balsamifera) (Fam. Salicacese). This tree is found 

 in the northern United States and British America, and its trunk 

 sometimes measures nearly 2 M. in diameter. In the early spring 

 the buds are gathered before they open. They are lanceolate- 

 cylindrical, with a broad base and sharp-pointed summit; from 20 to 

 25 mm. in length and about 5 mm. in diameter at the base, the ter- 

 minal buds being longer than the axillary ones. They are saturated 

 with a yellow balsamic exudation, which in the fresh buds is very 

 sticky, and are covered with fine oblong, pointed, concave, closely 

 imbricated, thick scales having a light-brown color and being very- 

 lustrous on the outer surface. These latter form a thin shell inside 

 of which at the base are the young leaves, with their protecting scales 

 and hairs, arranged on a cylindrical axis. They have a balsamic odor 

 somewhat suggestive of chamomile and an aromatic and bitter taste. 



The poplar buds contain 0.5 per cent of a light yellow volatile oil, 

 which is soluble in alcohol, and consists principally of humulene. 

 They also contain a soft balsamic resin, gallic acid; malic acid, salicin, 

 populin, mannit, chrysin, fixed oil and tectochrysin. 



The buds of other species of Populus are also said to furnish some 

 of the commercial article. The buds of the fir (Albies balsamea) 



