PAINTS, DYES, AND VARNISHES 



expensive colors used in painting." Since there is such 

 an array of these colors, many of which have been 

 named and renamed many times, it is obviously im- 

 possible to consider each in detail, and a description of a 

 few of the most important will suffice for our purpose 

 here. 



The original source of the finest of all pigments, car- 

 mine, was the North American continent, although the 

 cultivation of the cochineal insect, from which the color 

 is derived, has now extended to all tropical countries. 

 When the soldiers of Cortez first invaded the Aztec 

 empire in Mexico, they found the natives using a bril- 

 liant, red dye obtained from insects that were parasitic 

 upon certain cactus plants. Only the female insect 

 is used for coloring-material, the males being much 

 smaller and fewer in number. The female insects 

 cling to the cactus leaves in enormous numbers, from 

 which they are brushed onto heated metal plates, and 

 killed. 



These insects contain as high as fifty per cent, of 

 the coloring-matter called carmine, which is the same 

 name given to the lake made from it. It is obtained by 

 reducing the dried insects to a pulp, and afterward 

 macerating them in water. The coloring-matter is then 

 precipitated with an aluminum salt, great care being 

 taken to have all the materials used perfectly pure, as 

 any impurities affect the shade. Thus the impurities 

 contained in ordinary water, or even the minerals in 

 spring water, may injure the color if such waters are 

 used. It is customary, therefore, to use distilled water 

 in the process of manufacture. And the same care 



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