COCHINEAL 705 



vested and the manner in which the insects are killed. The most 

 valuable variety is known as " Madres " and represents the first 

 brood of the season. This corresponds to the variety formerly 

 known as " Zacatillo," which was exported from Mexico. At one 

 time Honduras shipped the best commercial article. At the present 

 time, the greater quantity comes from Teneriffe, one of the Canary 

 Islands. 



According to the fancy of the broker or exporter several grades 

 of cochineal are recognized. Broadly speaking, the terms " Silver 

 grain," " black grain," and " granilla " are used, but there are inter- 

 mediate qualities variously designated as gray, black-gray, silver- 

 gray, silver-black, rosy-black, red and foxy and these again may be 

 qualified by the terms fair, bold, fine and so forth. The commercial 

 variety known as " granilla " represents probably nothing more than 

 the smaller females in which the larva? usually show but a very slight 

 development. The color is due to the mode of preparation for the 

 market. If dried in trays in the sun, or in an oven at a moderate 

 temperature (about 65 C.) for four or five hours, and subsequently 

 in the sun, the waxy substance is not melted and the silver grain is 

 the result. If they are dried at a higher temperature than 106 C., 

 the melting point of the wax on hot iron plates, the black-grain is 

 the result. The red tint of the rosy-black is said to be produced if 

 they are put in bags and dipped in boiling water to kill them before 

 drying, and that of the foxy silver grain is produced by sifting the 

 insects when not perfectly dry so that some of the coloring matter 

 tinges the surface. The black grain usually obtains a higher price 

 than the silver grain. Both the black and silver grain are some- 

 times adulterated to meet the demand for a cheap article. The 

 black grain is sometimes met with having the concave side filled with 

 grains of a magnetic iron sand. The silver grain is said to be weighted 

 with sulphate of barium or carbonate of lead and the very white 

 appearance is given by powdered talc or other white powder. 



Literature. Kraemer, Amer. Jour. Pharm., 1913, p. 344. 



CANTHARIS. Cantharides. Spanish Flies. The beetle, Can- 

 tharis vesicatoria (Fam. Meloi'dffi). This coleopterous insect is 

 found upon certain shrubs of the Caprifoliacese and Oleacese, growing 

 in southern and central Europe. The insects are gathered during 

 June or July, by shaking the shrubs or beating them with poles, and 

 collecting the insects upon cloths spread upon the ground. They 

 are then thrown into suitable vessels, and killed by means of chloro- 

 form, ether, or similar drugs. After which they are carefully dried, 

 at a temperature not higher than 40 C. The commercial article 



