Application in Dt/eing. 59 



same, the whole of the blue colouring matter being removed 

 from the dyeing vessel at each operation. 



It is not advisable to continue more than six parcels of 

 goods without emptying at least half the contents of the dye- 

 ing vessel, and filling with fresh water ; but shades of olive or 

 brown must succeed without any addition of water. 



For all shades of olive and brown which may be considered 

 as the same colour, only varying in the proportions of red, 

 yellow or blue, entering into their composition ; fustic is em- 

 ployed for the yellow, the blue is given by the sulphate of in- 

 digo, and for the red, madder is used for all the light shades 

 of bronze approaching to green, and camwood for the darker 

 shades of olive and brown. — I shall without further observa- 

 tion state some processes. 



The light and green shades of bronze are generally dyed 

 after green in the same liquor. For 126lbs. of worsted stuffs 

 after light green, added S-ilbs. of mull madder, 14lbs. of fustic 

 in chips, 4lbs. of alum, Slbs. of red argol, zlbs. of sulphuric 

 acid, and 1 pint of sulphate of indigo; boiled the whole toge- 

 ther ten minutes, added 20 gallons of water, entered the goods 

 turning quickly and afterwards more slowly, boiled one hour 

 and thirty minutes, took out the goods and added 3 mea- 

 sured ounces of sulphate of indigo, entered and boiled thirty 

 minutes. With olives, and indeed all the colours in which 

 sulphate of indigo is employed except the very red browns, it 

 is of consequence that a portion should be added towards the 

 close of the operation, thus increasing the brilliancy of the 

 blue part of the colour, which is impaired by the long boiling 

 required to fix the yellow and red. 



In the same manner are dyed all the shades of olive, the 

 proportions varying with the colour required ; the amount of 

 mordant (alum) and acid employed, must diminish with the 

 number of operations that have been conducted without emp- 

 tying the dyeing vessel. 



In dyeing the red shades of brown for which camwood is 

 used, a different process is employed, the insoluble combina- 

 tion formed between its colouring matter and the base of alum 

 pi'events their being employed together. 



For 90lbs. of worsted goods in fresh water dyed in a leaden 

 vessel containing 300 gallons of water, added 15lbs of rasped 

 camwood, 9lbs. of rasped fustic, 12 measured ounces of sul- 

 phate of indigo, Slbs. of red argol, and Slbs. of sulphuric acid; 

 after boiling the whole together a few minutes, added 20 gal- 

 lons of cold water, and entered and boiled 1 hour; the goods 

 had ac(juired a dull red brown colour, took up, added 6lbs. 

 of alum, and H measured ounces of sulphate of indigo, en- 



I 2 tercd, 



