454 The Art of Dyeing. 



sisting of 1 lb. oil-soap, dissolved in 200 lbs. of boiling wa- 

 ter. This gives the dye a pink tint, while the yellow dis- 

 appears. A cold strong solution of carbonate of soda (54|° 

 to 66-f°) possesses a similar action. 



A solution of salt of tin in caustic potash employed in a 

 very dilute state, and cold, imparts more lustre to the 

 madder red. 



Properties of madder red. — This colour is very perma- 

 nent when exposed to air and light, although not so dura- 

 ble as Turkey red. 



By the common washing with soap, the dye acquires 

 brightness ; but is not much clearer if the solution employed 

 is too hot. 



Solution of potash makes the colour, when heated with 

 soap-suds, only a little darker. The colour is restored by 

 vinegar. 



Ammonia produces no change. 



Lime water makes a slight alteration, which disappears 

 by washing. 



Vinegar and Lime Juice produce no change. 



Tin mordant, No. 1 and 2, printed in a strong solution, 

 occasion no loss of colour 



Solution of chloride of Lime acts like the tin mordants. 

 When the dyed cloth is allowed to remain for two hours, 

 in a solution of 1 lb. chloride of lime in 40 lbs. of water, a 

 loss of colour, but not a complete bleaching is experi- 

 enced. 



YELLOW FROM PERSIAN BERRIES AND ALUM MORDANT.* 



The mordant employed is alum mordant, No. 3 : the cloth 

 is soaked in it, pressed and washed. The solution of alum 

 with soda may also be employed for mordanting in the 

 same manner. 



Dark berry yellow is produced by alum mordant, No. 2 ; 

 allowing the cloth to be soaked in it, pressed and then 

 dried. The mordanted cloth is cleared by rinsing it in 

 running water. Bran has an advantageous action in the 

 production of this colour, which becomes purer and clearer. 



* See Specimen, "Records of General Science," i. 325. — Edit. 



