Affinity of Cotton for Dyestuffs. 445 



madder, logwood, Persian berries, yellow wood, nutgalls, oak 

 bark, willow bark, quercitron, &c, it takes up a certain quan- 

 tity of each dye, which neither washing with cold or hot 

 water, can remove. The calico will thus, when madder 

 and yellow wood are employed, be faintly coloured, but 

 when immersed in a mordant, especially in alum and lime 

 water, becomes darker. Calico dyed in this way must be 

 wellboiled with ley and freed from all lime by means of sul- 

 phuric acid, otherwise spots will be formed. 



Nutgalls.— When 20 lbs. cloth are boiled in a solution 

 of 1 lb. nutgalls for half an hour, the former acquires a 

 pale yellow colour; but dipped in a solution of 10 lbs. 

 of iron alum, in 600 water, and rinsed in running water, 

 the colour becomes greyish lilac. 



The nutgall solution must be formed of a clear decoction 

 of nutgalls. If powder of nutgalls is employed, spots re- 

 main after the calico is rinsed with water. Hot soap-suds 

 impart to the colour a reddish tint, which looks well. 



Properties of the dyed cloth.— The colour loses none of 

 its depth, after boiling for a quarter of an hour ; but is 

 converted into a greyish brown. 



Solution of potash produces brown spots, which are 

 completely removed by vinegar. 



Lime water acts in the same manner. If the cloth is 

 moistened with lime water, it acquires a clear brown shade. 

 Solution of ammonia, much diluted with water, pro- 

 duces a similar effect : the colour, however, is less satu- 

 rated. 



Vinegar has noactionl 



Lime juice forms white spots, which ammonia turns 

 brown. Both of the Tin Mordants, No. 1 & 2, when printed 

 on it, discharge a pure white. 



Solution of chloride of lime, in the proportion of one 

 part chloride of lime to forty water, discharge white. 



Xutgalls and copper, or lime under. When calico, boiled 

 for half an hour in a solution of nutgalls, is well rinsed 

 and dipped in the copper mordant, No. 2, or in lime water, 

 a pale yellow coluur is produced. 



Properties of the cloth. — Cloth dipped in the copper mor- 

 dant, acquires by boiling with soap-suds, a greenish tint; 

 that dipped in lime water becomes somewhat paler. 



