GUTTA PERCHA 511 



Description. Purified gutta percha comes in flattened pieces of 

 variable sizes, and about 8 mm. in thickness; it is hard, rather 

 leathery, somewhat flexible and elastic, sinking in water, becoming 

 plastic at 65 C. and very soft, capable of being kneaded at a tempera- 

 ture of boiling water, and on cooling assumes its original form. 

 Externally, it is yellowish, grayish-brown or dark brown; porous, 

 somewhat fibrous and may be readily cut with a knife; internally it is 

 grayish-white to reddish-yellow and frequently with reddish-brown 

 streaks of darker colored' material; odor slight and somewhat 

 unpleasant. 



Gutta percha also occurs in the form of cylindrical sticks from 3 to 



5 mm. in thickness, having a white, grayish-white or yellowish color 

 and being somewhat pliable and elastic. 



Gutta percha is usually preserved under water, as when exposed 

 to the air it becomes brittle. It is insoluble in water, cold alcohol, 

 ether, dilute acids and dilute solutions of the alkalies. About 90 

 per cent is soluble in chloroform, carbon tetrachloride, carbon disul- 

 phide, petroleum ether and oil of turpentine. It is partly soluble in 

 boiling alcohol, and the filtrate, on cooling and evaporating, leaves a 

 crystalline residue. Gutta percha is not acted on by acetic or 

 hydrochloric acid; on the other hand sulphuric or nitric acid slowly 

 dissolve it. 



Constituents. From 80 to 85 per cent of an amorphous hydro- 

 carbon, gutta, which is soluble in chloroform, ether, petroleum ether, 

 paraffin oil, fixed and volatile oils. Two oxidation products of gutta 

 viz., (a) alban, from 4 to 16 per cent, which occurs as a whitish 

 amorphous resin, and is soluble in hot alcohol; (6) fluavil, from 4 to 



6 per cent, a yellowish amorphous resin, soluble in cold alcohol. It 

 also contains a complex product, guttan, which seems to resemble 

 gutta; and ash, from 3 to 5 per cent. Crude gutta percha contains 

 in addition a small quantity of tannic acid and a sugar-like substance. 



Literature. Zornig, Arzneidrogen. 



STYRACACEJ2, OR STYRAX FAMILY 



i 



A small family of about 75 species of trees and shrubs, mostly 

 indigenous to tropical South America, a few representatives being 

 found in the southern United States. The leaves are mostly simple 

 and alternate, the flowers are regular and either in axillary clusters 

 or racemes, and the fruit is either a berry, a drupe or a capsule. 

 Very many of the plants contain a benzoic resin. This occurs in 

 lysigenous, intercellular secretory receptacles, which develop in the 



