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DYEING AND CALICO PRINTING.

sumach,—and with “ barwood spirit,” a preparation of tin, receipts for whichwill be given in a special chapter. It is then boiled along with the loosewood. This process presents two interesting peculiarities : absolute contadbetween the ware and the mordanted goods appears necessary, and, unlikeordinary cotton-dyeing operations, it is carried on at a boiling heat. A reduc-tion of temperature is fatal to a good result.

Cam Wood or Kambe Wood.—This dye ware is brought from the Gaboonand Sierra Leone. It yields its colouring matter to water much more freely thanbarwood and sanders, but is still not sufficiently soluble to produce an extrad.The shades which it yields are, under all circumstances, more yellow thanthose produced by Brazil wood. It is used by woollen dyers to produce certainfast reds, maroons, and especially browns of a very permanent character. Italso serves as a ground or “ bottoming” for certain blues, whether producedwith the vat, extrad of indigo, or with anilines, especially Guernsey blue.

Logwood, or Campeachy.

Logwood, Campeachy wood, called formerly “ blue wood ” and “ blackwood,” is met with in commerce in the shape of large irregular-shaped blocks,weighing on an average about 400 lbs. Externally this wood is deep brown-red, but within, where no air has been in contad with it, its colour is brighter.It is very hard, and capable of taking a good polish ; the blocks or billets areusually full of cracks and crevices; its taste is saccharine and astringent, andit colours the saliva red.

The Hcematoxylon campechianum is the tree which yields the wood in ques-tion. This tree also belongs to the natural order Leguminosce, and is a nativeof the entire warmer portion of South America, the larger American Antilles,viz., Jamaica, Cuba, St. Domingo, and also of Mexico. This wood has beenknown and used in Europe from a short period after the discovery of America,and since 1715 the tree has been cultivated in Jamaica. This wood has been thesubjed of an Ad of Parliament, made in the twenty-third year of the reign ofQueen Elizabeth, by which its use was forbidden as a dye-material, because itdid not yield fast colours. This Ad of Parliament was repealed, or at leastsuperseded, by an order in council of Charles II., which sets forth thatwhereas great improvements had been made in dyeing generally, and greaterskill applied especially as regards the means of obtaining faster colours from“ black wood,” the dyers might be allowed to use it, and Elizabeth’s Ad mightremain in abeyance.

The following are the chief varieties of logwood, distinguished by nameschiefly derived from the localities of exportation ;—Spanish log, or campeachywood, from Yucatan and Mexico; English logwood, from Jamaica; woodfrom St. Domingo ; Honduras (British) wood ; Martinique, and Guadeloupeor French wood ; the last two kinds of less value as dye material than theothers.

To the researches of Chevreul (1810) and to those of the late Dr. Erdmann,and of Runge of more recent date, we owe our knowledge of the properties andcomposition of the colouring matters of logwood. The colouring matter oflogwood exists in the aqueous decodions of that wood in three differentforms:—In an oxidised state ; as colourable matter, and is then known by, ordesignated as, hasmatoxylin ; and, lastly, as a glucoside. The oxidised portion