616 



HISTORY OF THE VEGETABLB KINGDOM. 



in its wild state), three or four feet liigh, on a 

 thin, stony, undressed soil, apparently the vert/ 

 station it prefers. 



The Quercitron Oak Bark, though long in 

 common use in those countries where it is indi- 

 genous, was not introduced into England until 

 the year 1785, when Dr Bancroft firet applied it 

 to the purpose of dyeing, and obtained a patent 

 for its exclusive use. The qiiercus tinctoria, 

 which produces thisdyeing substance, has already 

 been described in the account of timber trees. 

 The quantity of colouring matter contained in 

 this bark is very great, compared to its weight; 

 while the beauty of the colour it imparts is 

 nearly equal to that of weld, and its durability 

 is superior. According to Dr Bancroft, it is 

 capable alone of producing more cheaply all, or 

 very nearly all, the effects of every other yellow 

 dyeing drug. Its value is now fully appreciated, 

 and a large quantity is annually imported from 

 America into this country. 



The epidermis, or exterior blackish coat of 

 this bark, affords a yellow colour, but less pure 

 than the other parts of the bark; it is therefore 

 separated from these, being shaven off with a 

 sharp instrument. The cellular and cortical 

 parts which remain are then ground in a mill, 

 some falling into a light fine powder, and the 

 rest into stringy filaments; this last yields only 

 lialf as much colouring matter as the powder. 

 These are seldom separated from each other, 

 however, but are used together as a dyeing sub- 

 stance. In this state the bark yields as much 

 colour as about eight or ten times its weight, and 

 one hundred times its bulk of the weld plant. 

 The colouring matter is readily extracted by 

 water, at a temperature of 100° Fahrenheit. 

 This decoction is of a brownish yellow colour, 

 which alkalis deepen and acids brighten. All 

 the different shades of yellow may be produced 

 by varying the quantity of colouring matter. 

 It is an adjective colour; the mordants used are 

 nitro-muriate of tin and acetate of alumina. 

 Drab colours are obtained from the same dye, 

 with a mordant of sulphate of iron and carbonate 

 of lime, and olive shades by a mordant of sul- 

 phate of copper and carbonate of lime. An 

 extract may be made from the bark amounting 

 to about one-twejfth of its weight, but its colour 

 becomes injured by the application of boiling 

 heat, and therefore the extract cannot be used 

 with advantage in dyeing. It would indeed be 

 a most valuable desideratum if the colouring 

 matter obtained from distant countries could be 

 brought in the foi-m of extract, thus concentrat- 

 ing all their virtues within the least possible 

 space. But hitherto all colours are found to be 

 injured while undergoing this process. The 

 chemist would render an acceptable service to 

 the arts who should discover means whereby 

 this purpose might be successfully accomplished. 



Quercitron bark is imported into England 

 under an impost of Sd. per cwt. : its price is 

 about 9s, per cwt. 



The average annual importation for the last 

 five years is 2,214 casks, containing ten cwt. 

 each. 



Fustic (morus tinctoria). Natural family 

 urticece; moncecia, tetrandria, of Linna:us. This 

 tree is a native of Brazil and of several of the West 

 India islands. It is tall and branching, with a 

 fine head, smooth leaves, and oval-shaped, solitary 

 spines. The whole plant abounds in a slightly 

 glutinous milk, of a yellow sulphureous colour. 

 The berries are sweet and wholesome, and fed 

 on by birds. 



The precise period of- its introduction into 

 Europe as a dyeing substance is not exactly 

 known, but it was certainly soon after the middle 

 of the seventeenth century, as at about that time 

 we find it noticed among the dyeing drugs in use. 

 It is now in very extensive demand in our dye- 

 houses under the name of fustic. 



This wood, which is of a sulphur colour, with 

 orange veins, abounds with colouring matter; it 

 may be used substantively, and is tolerably 

 durable, but it can be made extremely so when 

 in combination with the same mordants as are 

 employed with weld or quercitron. Though a 

 permanent dye, it is seldom used for pure yellow, 

 as the colour which it imparts is dull and muddy; 

 it is therefore chiefly employed in compound 

 colours. It goes much farther than weld, but 

 is not of so economical a use as quercitron. In 

 equal weights, quercitron yields four times as 

 much colouring matter as fustic, and their rela- 

 tive prices render the bark a cheaper dyeing 

 material. This wood is, however, found more 

 efficient in some mixtures of colours. It is much 

 employed in combination with indigo, to dye 

 what is called Saxon green. With an iron basis 

 it dyes drab, and with an aluminous basis olive 

 coloure. This colouring matter is never applied 

 to calico-printing, since the English dyers have 

 hitherto been unsuccessful in pi-oducing from it 

 any thing like an equal degree of clearness or 

 brightness witli that of weld or quercitron. 

 Chaptal gives a simple method of obtaining a 

 more lively colour from fustic. It consists in 

 merely boiling in a decoction of this wood shav- 

 ings of skin, glue, or other animal matter. The 

 stuffs dyed in this preparation will, according to 

 that eminent chemist, take a beautiful and most 

 intense colour. 



Fustic is imported into England in large quan- 

 tities, chiefly from Culia and Jamaica. That 

 from Cuba is very superior, and usually obtains 

 fifty per cent, higher price than that from 

 Jamaica. It is admitted into England at the 

 nominal duty of three shillings per ton from 

 British possessions, and of four shillings and 

 sixpence from other countries. Tiie average 



