454 The Art of Dying . 



second and third dyeing, the colours were lighter, so that 

 from this it appears, that the husks of 36 bran keep back 

 the half of the colouring matter of 12 madder, while the 

 corresponding quantity of bran in its natural state gives it 

 up and deposits it on the calico. This seems to shew, that 

 by washing the bran with water, substances are removed 

 which by the use of unwashed bran are precipitated simul- 

 taneously with the colouring matter upon the mordanted 

 calico, and assist in forming the madder- red. This also 

 explains the higher shade of the madder-red dyed with 

 bran. It yet remains to be explained, why cloth mordanted 

 with alum mordant, by boiling with bran, acquires the 

 property, after proper washing, of becoming blue in solu- 

 tion of iodine. This property of becoming blue certainly 

 only demonstrates the presence of starch in the calico ; but 

 it renders it highly probable, that other constituents of the 

 bran also combine with the calico. To ascertain this last 

 point, the relation of the washings of the bran to madder 

 in dyeing were also tried. The milky washings, but free 

 from husks, of 36 bran were mixed with 12 madder, and 

 therein 3 of mordanted cloth were three times dyed in 

 succession. Colours were obtained, which were equal, 

 though, when closely inspected, scarcely so clear as those 

 obtained in the usual way with bran. 



The last circumstance induced the following trial to be 

 made. The milky bran washings at 68° deposited, after 

 standing for two or three hours, a white mealy sediment, 

 and the solution assuming a dirty yellow colour. Both 

 the mealy deposit and the cold bran infusion were tested 

 as to their relations to madder. The action of the mealy 

 deposit, when well washed and dried, was similar to that 

 of wheat flour. 



Hence, it appears that the cold infusion of bran exhibits 

 the same action as frequently appears in dyeing. For its 

 employment, two lbs. of sifted bran wree stirred for the 

 space of an hour with 20 lbs. of water, then the solution 

 was let off, and after filtration added to the solution of 

 madder in different proportions instead of the bran. It 

 gave in the proportion of 3 lbs. of the cold infusion to 

 6 lbs. of Avignon madder in the first dyeing with 3 lbs. of 

 mordanted cloth, a very clear light red. The 3 lbs. of 



