Take one part by weight of alum finely powdered; dissolve it in as much hot water as is 

 necessary, and no more ; that is five pints of water and half a pint of vinegar to one pound 

 of alum. Then add to it three-fourths of a part of sugar of lead : stir them well, let them 

 settle, pour off the clear liquor after the sediment has settled for a day: add to each pint of 

 the clear liquor four ounces of gum arable, bruised into a coarse powder; keep stirring it 

 occasionally until dissolved. 



Divide your callicoe so cleared by an acid, into pieces of four or six inches square. In the 

 middle of each piece print a figure or make a spot with your thickened acetat of alumine. 

 Let it dry. Then let it soak for half an hour in a liquor composed of one part by measure 

 of fresh cow dung to four parts boiling water. Then take out the piece: rince it: dry it: lay 

 it by for use, to be dyed in the decoction of the proposed vegetable. Boil it, or rather keep 

 it in a full scalding heat of the decoction for an hour. Then boil it in bran and water, and 

 bleach it in the air for a day. 



4. Make a mordant of iron in the acetous acid thus: dissolve in four parts by weight of 

 hot water one part of green copperas; add more water if necessary when cold, to keep it in 

 solution. To this solution add an equal weight of sugar of lead. Let the sediment subside, 

 thicken the clear liquor with gum arable, and use it on the callicoe in the same manner as 

 you use the acetate of alumine. This will be the same with the common iron liquor. 



You may mix these two mordants at your pleasure, so as to produce browns, purples, 

 and chocolates, with reds; and olives, drabs, &c. with yellows. So, you may use for 

 mordanting the whole piece of callicoe, sulphat of iron (green copperas) either mixed 

 or unmixed with common alum-solution: for the colours are thus greatly varied with 

 the same drug, or colouring material. 



These mordants might be increased in number, and varied ; but then the experiments 

 would become too complicated, and would vary too much from the usual and approved 

 practice. 



I have stated in the beginning of this work, that the quantity and brilliancy of the 

 colouring matter of a dye-drug might be ascertained by a solution of acetat of alumine 

 of muriat of tin generally speaking. I prefer the former, particularly for cotton: but 

 the muriat or nitro-muriat of tin is very useful for colours to be applied to woollen. 



Make a filtered decoction of the vegetable to be tried : drop into it a solution of acetat 

 of alumine not thickened with gum, and a little diluted. Or, a saturated solution of 

 nitro-muriat of tin, wherein the muriatic is in the proportion of three parts, and the 

 nitric acid of one. 



The quantity and colour of the colouring matter may be thus ascertained. 



Such a course of experiments with the woods, herbs, fruits and flowers of our own 

 country, would be a very valuable and interesting work: that ought indeed to be a na- 

 tional work, but that is not to be expected. 



I have already mentioned that the birch tree, and the Lombardy poplar, promise 

 useful and permanent colours, and deserve to be the subject of many experiments not 

 yet made, particularly in the back country, for which these experiments seem peculiarly 

 calculated. 



Table and Classification of Colours procured from Indigenous Plants. 



According to the experiments of D'Ambourney. 



Homassel, or Bouillon Le Grange, have omitted the Linnaean names of the vegetables, 

 which I have supplied from D'Ambourney's original work. I cannot always answer for 

 the English names, though I believe there are very few mistakes; but as I have added 

 the Linniiean ones, there can be no difficulty to a botanist. 



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