382 MATERIA MEDIC A AND THERAPEUTICS. 



Composition. "Wax differs from ordinary fats in containing, 

 as its base, not glycerine, but another alcohol, melisyl-alcohol, 

 in union with palmitic acid, C3 H 61 O.Ci 6 H 31 2 . 



Preparations. 



Yellow and White Wax are used in preparing many Plasters, 

 Ointments, Suppositories, and Charta Epispastica. 



USE. 



Wax is used only for the pharmaceutical purposes just 

 mentioned. If given internally, it passes out in the faeces 

 entirely unabsorbed. 



HEMIPTEKA. 



Coccus COCHINEAL. The dried female insect, 

 Coccus Cacti. Reared in Mexico and Teneriffe. 



Characters. Ovate, plano-convex, about two lines long 1 , 

 wrinkled, black or greyish-white ; yields, when crushed, a 

 puce-coloured powder. The greyish- white insect quickly be- 

 comes black when warmed before the fire. 



Impurities. Inferior Cochineal is "faced" with various 

 white or black powders to improve its appearance. It resembles 

 Kino, which has an astringent taste. 



Composition. Cochineal contains a red colouring principle, 

 carmin or carminic acid, brownish-purple, amorphous ; readily 

 soluble in water and spirit. 



Preparations. 



Tinctura Cocci. 1 in 8. Dose, % to 1 fl.dr. 

 Coccus is also an ingredient of Tinctura Cardamomi Composita, 

 (60 gr. to 1 pint) ; and Tinctura Cinchonae Composita, 

 (30 gr. to 1 pint). 



ACTION AND USES. 

 Cochineal is used as a colouring material only. 



COLEOPTERA. 



Cantharis CANTHARIDES. Cantharis vesica- 

 toria. The Beetle, dried ; collected chiefly in Hungary. 



Characters. From eight to ten lines long, furnished with 

 two wing-covers of a shining metallic-green colour, under 



