COCHINEAL 87& 



gelatinous deposit from three to four times its volume of freshly-deposited alumina, 

 obtained by the addition of carbonate of soda to a solution of common alum. This 

 mixture, after being well dried, calcined, and ground, affords a blue pigment. 



COBALT BRONZE. A violet-coloured substance, with strong metallic lustre. 

 It consists of phosphate of protoxide of cobalt, and phosphate of ammonia. 



COBALT, EARTHY. A protoxide of cobalt with oxido of manganese, from 

 Saalfeld, in Thuringia. 



COBALT GLANCE. A synonym for cobaltine. See COBALT. 



COBALT GREEN, or Einmann's Green. This pigment is a compound of oxide 

 of cobalt and oxide of zinc. It is prepared by mixing a solution of sulphate of zinc 

 with a salt of protoxide of cobalt, and precipitating with carbonate of soda ; the 

 precipitate is then washed, dried, and heated. 



COBALT SPEXSS. A substance obtained in the preparation of smalts, and 

 consisting chiefly of arsenide of nickel, derived from the nickel associated with the 

 cobalt ore. The speiss is used in the manufacture of nickel. 



COBALT ULTRAMARINE. Thenard's Blue. See COBALT BLUE. 



COBALT YELLOW. An orange-yellow pigment precipitated from an acidified 

 solution of nitrate of protoxide of cobalt by means of nitrate of potash. 



COCA. The leaves of Erythroxylon coca ; mixed with burnt lime they are 

 chewed by the natives in parts of South America. See EEYTHEOXTLON COCA. 



COCCOZiOBTTS. (/cd/c/coy, a berry ; AojSck, a pod.) The Coccolobus unifera, or 

 seaside grape, is a tree about twenty feet in height, with leaves of a glossy green 

 colour the nerves being a deep red. The fruit is in bunches, and is eaten in the 

 West Indies. The wood yields a red colouring matter, which is used for a dye ; and 

 the wood itself, which is hard, is employed in cabinet work. A decoction of this plant 

 is evaporated to form a substance known as Jamaica Kino. 



C OCCtriiUS INDXCUS, or Indian berry, is the fruit of the Anamirta paniculata, 

 a large' tree, which grows upon the coasts of Malabar, Ceylon, &c., and belongs to the 

 Menispermacea or Moon-seed order. The fruit is blackish, and of the size of a large 

 pea. It owes its narcotic and poisonous qualities to the vegeto-alkaline chemical 

 principle called picrotoxia, of which it contains about one-fiftieth part of its weight. It 

 is sometimes thrown into waters to intoxicate or kill fishes ; and it is said to have 

 been employed to increase the inebriating qualitites of ale or beer. Its use for this 

 purpose is prohibited by Act of Parliament, under a penalty of 20 01. upon the brewer, 

 and 500Z. upon the seller of the drug. 



However, Dr. Pereira states, ' I am not acquainted with any official returns of the 

 quantity annually brought over. From a druggist's private books I find that in 1834 

 above 2,500 bags entered and this probably is much below the quantity imported. 

 The greater part is consumed for illegal practices principally for adulterating ' beer 

 and ale.' Morrice, in his treatise on brewing, directs that in the manufacture of 

 porter, three pounds of Cocculus indicus should be added to every ten quarters of malt. 

 ' It gives,' says he, ' an inebriating quality, which passes for strength of liquor ; ' and 

 he adds, ' that it prevents the second fermentation in bottled beer, and consequently 

 the bursting of the bottles in warm climates.' 



The Editor of this work had a fluid extract, the name of which was unknown to 

 the Custom-house officers, submitted to him some years since. This was an extract 

 of this deleterious drug, of which a very large quantity was then in the London 

 docks. 



The powder of the berries mixed with lard is used to destroy pediculi : hence the 

 Germans call those grains Ldusekorner, or lousegrains. 



COCHINS AIi. (Cochenille, Fr. ; Kochenttle, Ger.) Cochineal was first taken 

 for a seed, but was proved by Leeuwenhoeck to be an insect, the female of that species 

 of shield-louse, or coccus, discovered in Mexico so long ago as 1518. It is brought to 

 us from Mexico, where the animal lives upon the Cactus opuntia or Nopal. Two sorts of 

 cochineal are gathered : the wild from the woods, called by the Spanish name Grana 

 silvestra; and the cultivated, or the Grana fina, termed also Mestegue, from the name 

 of a Mexican province. The first is smaller, and covered with a cottony down, which 

 increases its bulk with a matter useless in dyeing ; it yields, therefore, in equal weight, 

 much less colour, and is of inferior price to that of the fine cochineal. But these dis- 

 advantages are compensated in some measure to the growers by its being reared more 

 easily and less expensively ; partly by the effect of its down, which enables it better 

 to resist rains and storms. 



The wild cochineal, when it is bred upon the field nopal, loses in part the tenacity 

 and quality of its cotton, and acquires a size double of what it has on the wild 

 opuntias. It may, therefore, be hoped that it will be improved by persevering care in 

 the rearing of it, when it will approach more and more to fine cochineal. 



The fine cochineal, whn well dried and well preserved, should have a grey colour 



