DYEING. 



223 



Substantive 

 Colouring 

 Matters. 



Other kinds 

 of archil. 



latile alkali which lias formed, to evaporate, that the ar- 

 chil may have the violet smell of that which is well pre- 

 pared. To preserve it any length of time, however, it 

 must be kept moistened with urine. 



The test kind of archil is extracted from the rocella, 

 or orchella ; but this colouring matter is obtained from 

 several other species of lichens. The French have long 

 employed for this purpose a kind of lichen called perelle, 

 which commonly adheres to volcanic stones or produc- 

 tions. The plant in question has been generally repre- 

 sented to be the lichen parellus of Linnaeus ; but this 

 supposition is disproved by a memoir of M. Cocq, lately 

 published in the 81st vol. of the Annalcs tie Cldmie. He 

 states, that in Auvergne, where the perelle is principally 

 gathered, the true lichen parellus is called la pommelee, 

 and is always rejected as unfit by the persons employed 

 for this purpose. M. Cocq describes, in the same me- 

 moir, the process by which the perelle is prepared at 

 Clermont for the use of the dyer. It appears, that the 

 perelle is macerated and fermented in wooden troughs, 

 which are commonly about six feet in length, two or 

 three in breadth, (contracting towards the bottom), 

 and about two feet in depth. Each trough is furnish- 

 ed with a cover, which fits it exactly, and retains as 

 much as possible of the volatile alkali of the human 

 urine. * About 200 libs, of perelle and 240 libs, of 

 urine are mixed together in each trough, and afterwards 

 stirred every three hours, during two days and nights, 

 taking off the cover only as often and as long ns is ne- 

 cessary for the stirring. On the third day, 10 libs, of 

 sifted and slacked lime must be added, and well mixed, 

 together with a quarter of a pound of arsenic, and an 

 equal weight of alum. The workmen must avoid the 

 fumes of the arsenic as much as possible, for some hours 

 after its admixture. The stirring is then to be repeated 

 several times, once every quarter of an hour, and after- 

 wards every half hour, till the fermentation i* establish- 

 ed ; when this is the case, the mixture need not be stir- 

 red more frequently than is necessary to prevent a 

 crust from forming on the surface, which, by obstruct- 

 ing the fermenting process, would resist the complete 

 evolution of the colour. After th fermentation has con- 

 tinued 48 hours, it commonly begins to diminish, and 

 must be renewed by the addition of two libs, more of 

 sifted lime, and the stirring continued once every hour 

 until the fifth day, when the frequency of stirring may 

 be gradually diminished. After the eighth day, it is 

 sufficient to stir the mixture every six hours, extending 

 the process a fortnight, and even in some cases three 

 weeks longjer. The colouring matter thus prepared, is 

 afterwards to l>e kept moist in close casks. It improves 

 during the first year; suffers little change during the 

 second ; the third, it begins to decline, and becomes in- 

 ferior in quality afterwards. 



88. During a very long period, the inhabitants of 

 Sweden, Scotland, Ireland, and some of the northern 

 parts of England, have been in the practice of dyeing, by 

 means of different species of lirhen, macerated in urine. 

 Of these, the Liclteii oinp/ialidef has been much used, un- 

 der the name of cork, rurktr, and a real ; in Wales it is 

 called kfnkcrinit. This lichen {lives a dark crimson to 

 wool and woollen stuffs. Linna-us says, that it is pro- 

 duced in great abundance in the island of Aland, in the 

 Baltic. The Lichen Tarlareus, which grows on lime- 

 stone rocks, yields a similar colour, and has been long 



Substantive 

 Colouring 

 Matters. 



used as a dye by the peasants of Wales and the Orkneys. 

 The inhabitants of West Gothland prepare a beautrml 

 crimson dye from this lichen, which, under the name of 

 By/telel, is used over all Sweden. It also forms an ar- 

 ticle of exportation, and is known in this country by the 

 name of Cudbear, a name given to it by the late Dr Cudbear. 

 Cuthbert Gordon, who obtained a patent for its prepara- 

 tion. At the proper season, and in places where the Li- 

 chen Tartareus is produced, one person may collect from 

 twenty to thirty pounds of it daily. It should be allow- 

 ed five years growth before it is gathered ; and it is (ire- 

 pared for use by washing and drying it, which commonly 

 reduces it to half the original weight. It is macerated 

 and stirred in wooden troughs, in the same manner as 

 the perelle at Clermont ; only aqua ammonia prepared 

 from human urine is employed, instead of urine itself. 

 Dr Bancroft, who has frequently prepared the colouring Dr Bpn 

 matter yielded by this lichen, states that the ammonia has croft's" me* 

 important advantages over the urine ; and that he is con- tliod of pre* 

 vinced that the alum recommended by Bocq is complete- P arin S iu 

 ly useless, while the arsenic is not only useless, but dan- 

 gerous. He also thinks that much labour in stirring, 

 and much waste of volatile alkali, might be avoided, by 

 employing hogsheads instead of fixed troughs. For this 

 purpose, he recommends the lichen to be first ground in 

 a mill, and afterwards to be introduced into the hogs- 

 head along with a suitable quantity of liquid ammonia. 

 The bung-hole being well secured, the hogshead might 

 be rolled from time to time, or subjected to any other 

 kind of agitation. 



89. The colours obtained from cudbear prepared by Archil afv 

 these processes, possess great beauty and lustre at first, fords ." 

 but they quickly fade, and ought never to be employed, bu u^ ivc 

 unless for the purpose of heightening the brilliancy of dye. c 

 some more permanent dye. The colour extracted from 



the rocella, or orchella, is more beautiful and less fugi- 

 tive than that yielded by any other species of lichen ; 

 but none of these colours are lasting. Cudbear is chiefly 

 employed in this country to give body and lustre to the 

 blues dyed with indigo; it is also sometimes used as a 

 ground for madder reds. It stains marble of a durable 

 violet colour. Dufay says, that he has seen marble 

 stained with this colour unaltered at the end of two 

 years. 



90. The infusion of archil is of a crimson, inclining to Effect* of a- 

 violet. Acids impart to it a red colour : but as it con- l um an( l "- 

 tains ammonia, by which its natural colour has been al- tr -. munatc 

 ready modified, fixed alkalies produce little change on it, ^ *' 



only rendering its colour somewhat deeper, and more 

 inclined to violet. Alum forms with it a dark red preci- 

 pitate, without rendering the colour more permanent. 

 The nitro-muriate of tin makes the colour dyed with it 

 to approach nearer to a crimson, which is less fugitive 

 than when that ingredient is not employed. 



91. Besides the lichens, whose colouring matter is pre- 

 pared with ammonia, some of them afford substantive dyes 

 less beautiful, but more permanent, by mere boiling with 

 water. Of these, the musctis pulmonarius of Caspar Bau- 

 hine, or the lichenoides pulmonium reticulatum vulgare 

 marginibus peltiferis of Dillenius, known in the northern 

 parts of England by the name of rags, or stone-rag, dyes, 

 without any mordant, a very durable dark-brown colour 

 upon white wool or cloth; and a fine lasting black upon 

 wool or cloth which has previously received a dark blue 

 from indigo. See Bancroft, Perm. Col. i. 305. 



* This is contrary to That in recommended by Bertliolkfr. 



