202 The Art of Dyeing. 



It does not signify much in what proportion the copper 

 mordant is diluted with water, for it is remarkable, that 

 calico is not more strongly mordanted by solutions of 1 to 

 4, than of 1 to 16. 



It is, therefore, more profitable to dilute it to the last 

 state; or to add to 10 lbs copper mordant No. 1, 160 lbs. of 

 water. This is termed Copper Mordant No. 2. 



A cheaper copper mordant to be used on colourless 

 grounds is obtained by the following formula :—(l .) Let 

 3 lbs. of lime be dissolved of a thin liquid consistence, and 

 w^hileyet warm, be well mixed and stirred with a solution of 

 12 lbs. sulphate of copper in 200 lbs. water. (2.) Let 3 lbs. 

 of lime, in the same state, be mixed with a solution of 5 lbs. 

 sal-ammoniac in 600 lbs. water, well stirred and covered. 

 After twelve hours, both mixtures should be poured toge- 

 ther with the sediment collected. The blue solution now 

 formed is ammoniuret of copper or copper mordant No. 2. 



BLUE FROM COPPER MORDANT No. 2, AND LOGWOOD. 



When a darker colour cannot be obtained by employing a 

 stronger mordant, it is necessary in order to obtain darker 

 shades, to mordant twice and dye twice. The light blue is 

 first dyed ; this is again impregnated with the copper mor- 

 dant No. 2, and re-dyed with logwood. The dyeing solu- 

 tion contains lib. logwood, 3 lbs. bran, for 10 lbs. of mor- 

 danted cloth. The dyeing is performed by a steady heat 

 and long boiling. At first, the solution is very blue, but is 

 gradually removed. Boiling soap-suds renders the colour 

 of the blue vat similar. 



Properties of Logwood Blue. — Boiling this colour with 

 soap-suds for a quarter of an hour is rather advantageous 

 than prejudicial. 



Solution of potash produces white spots, which vinegar 

 completely removes. 



Lime-water, ammonia, and vinegar have no action upon it. 



Lime-juice makes orange-yellow spots, which ammonia 

 so far dissolves as to make the blue only a little lighter 

 than formerly. 



Both tin mordants, when printed on it, discharge a 

 purple red. 



Solution of chloride of lime, in the proportion of 1 to 40 

 water, discharge a pure white. 



