DYEING. 



tuVes of the simple colours, though in a 

 few instances substances are found which 

 produce some of the compound colours 

 without addition. 



To dye woollen green, either a blue 

 or a yellow dye may be first given to it ; 

 but the first is generally done, because 

 the yellow dye of the stuff would injure 

 the blue bath. The intensity of the blue 

 must be proportioned to the shade of 

 green required. When the blue dye is 

 given, the yellow is communicated by 

 some of the processes described. The 

 cloth, having first got the proper ground, 

 is washed at the fulling mill, and boiled 

 as for the common process of weld- 

 ing ; but when the shade is to be light, 

 the proportion of salts should be less. In 

 this case the quantity of weld used should 

 also be less, but for all other shades it 

 should be greater than for dying simple 

 yellow. 



Sulphate of indigo is employed for the 

 greens called Saxon greens. Dr. Ban- 

 croft directs for this dye, that from six 

 to eitjht pounds of quercitron bark, en- 

 closed in a bag, should be put into the 

 bath for every hundred pounds of cloth, 

 with only a small proportion of water, 

 just as it begins to grow warm. When 

 the water boils, six pounds of murio- 

 sulphate of tin should be put in, and a 

 few minutes after, about four pounds of 

 alum ; these having boiled five or six 

 minutes, cold water should be added, 

 and the fire be diminished, so as to bring 

 down the heat of the liquor nearly to 

 what the hand is just able to bear ; im- 

 mediately after this as much sulphate of 

 indigo is to be added, as will suffice to 

 produce the shade of green required, 

 taking care to mix it thoroughly with the 

 bath. The cloth, previously scoured and 

 moistened, should then be expeditiously 

 put into the liquor, and turned very brisk- 

 ly through it for a quarter of an hour, 

 that the colour may apply itself evenly 

 in every part. By these means very full 

 even, and beautiful greens may be dyed 

 in half an hour ; but during this.space it 

 is best to keep the liquor a little below 

 the boiling heat. 



Of dyeing Silk green. 



The silk is first scoured, as for other 

 colours ; and for light shades the scour- 

 ing must be as complete as for blue. It 

 is then first dyed yellow in small parcels, 

 (after being well alumed, and slightly 

 washed at the river) by carefully turning 

 it in the weld bath. When it has ac- 



quired the proper shade of yellow for the 

 green required, which is known by try- 

 ing a pattern in the blue vat, it is taken 

 out, washed, and then immersed in the 

 blue vat. A deeper colour is given, and 

 the shade varied, by adding a decoc- 

 tion of logwood, fustic,' or anotta, to the 

 yellow bath, after the weld has been 

 taken out. For light shades a lighter 

 ground is given/ 



For Saxon green from sulphate of in- 

 digo, the silk is prepared by boiling as 

 for welding, and afterwards washed. 

 Then fustic in chips, enclosed in a bag, is 

 put into the same bath, boiled for an hour 

 and a half, and then taken out, and the 

 bath let to cool till the hand can bear its 

 heat. A pound and a quarter of indigo 

 is added for every eighteen yards of 

 stuff; the stuff .should be first turned 

 quickly, and afterwards more slowly, 

 and it should be taken out before the 

 bath boils. 



In Dr. Bancroft's process for the Saxon 

 green, four pounds of quercitron bark, 

 three pounds of alum, and two pounds 

 of murio-sulphate of tin, are infused in a 

 proper quantity of water : the bath is boil- 

 ed ten or fifteen minutes, and when cool- 

 ed till the hand can bear it, is fit for use : 

 by adding different proportions of sul- 

 phate of indigo, various beautiful shades 

 of green may be obtained. Care must be 

 taken to keep the bath constantly stirred, 

 to prevent the colouring matter from 

 subsiding.' Those shades which are in- 

 tended to incline to yellow should be 

 dyed first ; and by adding sulphate of in- 

 digo, the green having a shade of blue 

 may be obtained. 



Of dyeing Cotton and Linen green- 



Cotton and linen are scoured in the 

 usual way, and then first dyed blue ; after 

 being cleaned, they are dipped in the 

 weld bath, to produce a green colour. 

 The strength of the blue and yellow is 

 proportioned to the shade of green want- 

 ed. But as it is difficult to give cotton 

 velvet an uniform colour in the blue vat, 

 it is first dyed yellow with turmeric, and 

 the process completed by giving it a 

 green by sulphate of indigo. 



The different shades of olive, and 

 drakes-neck green, are given to cotton 

 thread, after it has received a blue 

 ground, by galling it, dipping it in a 

 weaker or stronger bath of iron liquor, 

 then in the weld bath, and afterwards in 

 the bath with sulphate of copper ; the 

 colour is lastly brightened with soap. 



