380 VEGETABLE SUBSTANCES. 



It is generally supposed by the cultivators that the 

 colouring matter is contained in the whole plant, but 

 some assert that the valuable part resides in the 

 seeds alone, and they therefore consider it a very in- 

 judicious practice to reserve the whole plant for sale, 

 as the seeds are much wasted, not only by being 

 shaken while the stalks are formed into bundles, but 

 subsequently in the transport of these from one place 

 to another. Nor is this the only disadvantage ; the 

 carriage of so bulky an. article very much enhances 

 its cost, while if the seeds alone were an article of 

 commerce, their transport from one place to another 

 would be comparatively trifling. The plants occu- 

 pying a space of six cubic feet would not yield more 

 than half a peck of seeds *. This simple fact might 

 be ascertained without much difficulty, and if the 

 seeds were found to be really the only useful part, 

 surely the dyer would be loath to encumber himself 

 with the whole plant. It is, however, still put into 

 the dyer's pot, occupying one hundred times more 

 space than the quercitron bark, containing an equal 

 quantity of similar colouring matter. This is one of 

 the strongest grounds for preference that has been 

 brought forward by Dr. Bancroft in favour of that 

 bark. 



The beauty of the weld colour, however, notwith- 

 standing the great bulk of the article, as compared 

 with other dyes, causes it to be much used by dyers, 

 calico-printers, colour-makers, and paper-hanging 

 manufacturers. It is as adjective colour, but tole- 

 rably permanent when used with alum and tartar as 

 a mordant. 



In the year 1773 the sum of two thousand pounds 



was granted by act of parliament to a Dr. Williams, 



as a reward for his discovery of a fast green and 



yellow dye on cotton yarn and thread. This sup- 



* Philosophical Magazine, vol. xiii. 



