PEODUCTS AND THEIR APPLICATIONS. . 93 



29. COLORING MATERIALS— Continued. 



b. Derived from birds : 



Shell of eggs, used for white pigment. 



Series of murexides, or purpurate of ammonia dyes, made 

 from guano. 



c. Derived from fishes : 



(Essence cVOrient, or fish-scale pearl, used as a pigment.) 

 (Gall of carp, used in Turkey as a green paint and in staining 

 paper.) 



d. Derived from insects: 



(Cochineal dye, from Coccus cacti of Mexico, used in manu- 

 facture of rouge, of carmine, and lake pigments, and in 

 coloring tinctures.) 

 Canadian cochineal. 



(Kermes(and other cochineals of commerce, Coccus ilicis.) 

 (Lac dye and lac lake, from Coccus lacca, C. polonicus, C. uva 



ursi, and Opliis fabce.) 

 Dye prepared from bed-bug, (Gimex lectularius.) 

 (Dye prepared from Trombidium, in Guinea and Surinam.) 

 Nut-galls produced by insects, and used in tanning, for black 

 dyes, for woolen cloth, silk, and calico, and in manufacture 

 of ink and gallic and pyrogallic acid, employed in photog- 

 raphy. 



e. Derived from mollusks : 



(Sepia from Sepia officinalis.) 



Purple dyes from gastropods, Muresc, Purpura, &c. 



Purple dyes from nudibranch mollusks. 



30. CHEMICAL PRODUCTS AND AGENTS EMPLOYED IN 

 ARTS AND MEDICINE. 



a. Derived from mammals : 

 Secretion of skunk. 



Album grwcum of dogs, used as a depilatory in tanning hides. 

 Albumen of blood, employed in sugar-refineries, in certain 



cements and pigments, and as antidote and emollient. 

 Dung, used in calico-printing. 

 Gall of animals, used in mixing colors, in fixing the lines of 



crayon and pencil drawings, in preparing the surface of 



ivory for painting, in removing grease, and in medicine. 

 Pepsine and pancreatine, prepared from stomachs of hogs and 



calves. 



