74 



able quantity of coarse herbage, which in the winter 

 and spring months is of great importance to the 

 young cattle brousingin the pastures. The use of 

 this dyer's broorn is to prepare woollen cloths for 

 the reception of another colour. It communicates 

 to the article a dull yellow, which will then, by 

 being dipped in another liquor, or composition, 

 according to the shade required, receive a green 

 hue. Vegetable filaments, cotton, flax, See., are 

 very differently formed from those threads afforded 

 by animals, as silk and wool, and are differently 

 disposed to receive colours. The dye that will 

 give a fine colour to the one, is perhaps rejected by 

 the other ; and this plant is rarely or never used 

 by the dyer for cotton articles. That certain na- 

 tural productions receive and retain, and others 

 reject, or soon part with, artificial colourings, are in 

 some cases in consequence of the nature of the sub- 

 stance, and in others by reason of the conformation 

 of the fibre ; but any examination of this kind would 

 only occasion a tedious discussion, and remain very 

 obscure at last. We find certain effects produced 

 and reason upon them, but so small are the parts 

 operated upon, minute the agents, and equivocal the 

 connexion, that we can do little more than theorize 

 upon the subject ; but, perhaps, I may slightly in- 

 stance the difference existing in the fibre of flax 

 and silk. The parts which compose the filaments of 

 the former are generally considered as being flat 

 and flaky, whereas those of the latter are tubular 

 and round : this conformation renders silk so soft to 



