384 The Art of Dyeing. 



trials upon a large scale, where the quantities are only esti- 

 mated by the weight in the hand. It is astonishing how 

 little this has hitherto been attended to, and yet there is 

 nothing of greater importance in a dye- work. 



The proportion of the dyeing materials to the cloth to be 

 dyed is especially to be attended to ; the latter must never be 

 estimated by the volume, but by the weight. With the 

 same madder and the same cloth, a red, or a brownish-red, 

 is produced, according as the same, or a double quantity, is 

 employed for dyeing. Thus, logwood gives with the same 

 mordant a lilac and a blackish-blue, when it is employed in 

 small or great proportion. 



The same rule holds with other colouring matters ; and 

 the shade of the colour required can never be estimated 

 with accuracy, when the proportionate weight of the cloth 

 to be dyed is not known. Hence, often nothing at all is 

 learned from large and prolix treatises upon new colouring 

 matters, as this important point is omitted ; and the dyer, 

 who has not accustomed himself to make trials accurately 

 with grains or half ounces, but has been in the habit of em- 

 ploying pounds, and obtaining the same results on a large 

 scale, will require to be content with many spoiled pieces. 



When the dyer approaches the point where he obtains 

 the darkest colours with the smallest quantity of dye, it is 

 important to know its dyeing power ; this is effected in the 

 following manner : — 



A piece of calico, impregnated with No. 1. mordant, and 

 well washed, should be cut into equal portions of about two 

 square inches each. Weigh out, then, \, £, or -^ of a loth 

 (•468 oz.), or even less ; about ten to five grains of the co- 

 louring matter to be tested ; place it, with the requisite 

 quantity of water, in a porcelain dish over a spirit of wine 

 lamp, and dye the pieces of calico in succession until the 

 solution is exhausted, and the calico takes up no more co- 

 lour. Each bit of dyed calico should be first rinsed in a 

 little water, and this water should be again added to the 

 original solution, so as to lose no colouring matter. The 

 dyed pieces are then to be laid together when they are dried, 

 and those are to be picked out which are equally saturated, 

 and weighed. The weight gives the quantity of mordanted 



