444 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



THE POWDER is bright yellow, sternutatory, and contains few 

 or no starch grains; not more than 25 per cent should be insolu- 

 ble in alcohol. The resin is soluble in solutions of the alkalies, 

 with the production of an orange-red color. 



Constituents. Gum allied to arabin, 15 to 20 per cent; a resin 

 known as cambogic acid, from 65 to 75 per cent; a volatile oil; ash, 

 1 to 3 per cent. 



Cake Gamboge is collected in Saigon and Cochin from the same 

 plant that yields pipe gamboge. The product is, however, collected 

 in leaves and then allowed to dry. It occurs in irregular orange-red 

 masses, weighing 1 to 2 K., and is not so brittle as pipe gamboge, 

 but is less uniform in composition and may contain impurities. 



Allied Plants. A drastic gum-resin is also obtained from Garcinia 

 Morella and other members of the Guttiferae, of India and Malaya, 

 as G. collina, of New Caledonia; Vismia laccifera, of Brazil; Clusia 

 rosea, of the West Indies and South America, and Clusia macrocarpa, 

 of Guiana. Gamboge of a poor quality is obtained from Arasina 

 Gurgi, of India. 



Adulterants. Gamboge is sometimes adulterated with vegetable 

 fragments, inorganic substances, as sand, etc., and wheat or rice 

 flour, which the powdered drug may contain to the extent of nearly 

 50 per cent. 



CISTACE^E, OR ROCKROSE FAMILY 



A family of low shrubs and herbs, of which there are about 150 

 species. They are found chiefly in the northern countries of both 

 hemispheres. They possess simple leaves, regular and perfect 

 flowers, capsular fruits, and are especially characterized by their 

 thick-walled, unicellular hairs, which are frequently united, forming 

 stellate groups (Fig. 194). The glandular hairs are always uniseriate 

 (Fig. 194). As pointed out by Holm the pericycle is a continuous ring 

 including both sclereids and stereids, the former being in the nature 

 of stone cells and the latter being in the nature of lignified scleren- 

 chymatous fibers. The tracheae are provided with simple pores and 

 possess small lumina; the wood fibers have bordered pores; and the 

 medullary rays are narrow. Calcium oxalate is secreted in the form 

 of rosette aggregates. 



HELIANTHEMUM. Frostweed, Frost-wort. The over-ground 

 plant of Helianthemum canadense (Fam. Cistacese) a low shrub 

 growing in dry, sandy soil from Massachusetts to North Carolina. 

 The stem portions, with leaves and flowers, are collected in summer 

 and carefully dried. 



