BENZOINVM. 281 



Composition. Guttapercha contains 80 per cent, of a 

 hydrocarbon autta, salts, volatile oil, fat, colouring matter, and 

 two bodies named alban 



Preparation. 



Liquor Guttapercha. 1 in 8 of Chloroform, with 1 of 

 Carbonate of Lead ; by solution and decantation. 



USES. 



Guttapercha is employed for making surgical instruments 

 an.d apparatus. The solution is used in Charta Sinapis. 



STYRACACE^E. 



Benzoinum BENZOIN. A balsamic resin ob- 

 tained from Styrax Benzoin. It is procured by 

 making incisions into the bark of the tree, and allow- 

 ing the liquid that exudes to concrete by exposure to 

 the air. Imported from Siam and Sumatra. 



Characters. In lumps, consisting of agglutinated tears, or 

 of a brownish mottled mass with or without white tears imbedded 

 in it ; has little taste, but an agreeable odour ; gives off, when 

 heated, fumes of benzoic acid ; is soluble in rectified spirit and 

 in solution of potash. 



Substances resembling Benzoin : Gum resins, and resins dis- 

 tinguished by odour and taste. 



Composition. Benzoin consists chiefly of four different 

 resins, imperfectly known, with the officinal benzoic acid, 

 cinnamic acid, and a trace of volatile oil. 



Preparations. 



1. Adeps Benzoatus. 10 gr. to 1 oz. 



2. Tinctura Benzoin! Composite. " Friar's Balsam." Benzoin, 



8 ; Prepared Storax, 6 ; Balsam of Tolu, 2 ; Socotrine 

 Aloes, about 1; Spirit, 80. Dose, % to 1 fl.dr. 



From Benzoinum is made : 



Acidum Benzoicum. Benzoic Acid. HC7H 6 2 . Source. Pre- 

 pared from Benzoin by sublimation. Characters. Light 

 feathery crystals, nearly colourless, having an aromatic 

 odour. Soluble in 400 of cold water, in 12 of boiling 

 water, in 4 of spirit. Phosphate of soda or borax aids 

 its solubility in water, so that 1 of borax and 1 of acid 

 are soluble in 100 of water. Dose, 10 to 15 gr. 



