410 AN]N"UAL REPORT SMITHSONIIAN INSTITUTION, 195 



paste form, and it was in this manner that other nations obtained 

 their dye from Florence until they succeeded in obtaining the formula 

 for making it, and developed the skill for preparing it. In the old 

 English method the lichen was cut small or reduced to a powder by 

 passing it through a sieve, and placed in iron drums provided with 

 paddles. The mass was moistened slightly with stale urine, the mix- 

 ture being stirred once a day with additions of soda for 5 or 6 days at 

 a temperature of 35° to 45° C. Fermentation proceeded and was 

 checked frequently until the coloring matter, a dove gray, ceased to 

 increase. The product, orchil paste, was then placed in wooden casks 

 and covered with lime water or gypsum solution until needed by the 

 dyer. To make orchil liquor the lichen was treated with water and 

 urine and permitted to ferment as for orchil paste, after which the 

 fibrous matter was removed and the liquor collected and stored. Sal 

 ammoniac and saltpeter were sometimes used in the process. Dil- 

 lenius, 1741, "reckoned [the color] more beautiful when first dyed, than 

 the Tyrian Blue," while Bancroft (13) , in 1832, described the infusion 

 of orchil as of a red crimson inclining to violet. 



Modern methods are based on more accurate knowledge of the chem- 

 istry of the lichen dye. According to Hill (13), the lichen is sprayed 

 with ammonia until the mass turns color, when the blue orchil liquor 

 is extracted with water ; if heated until the ammonia is driven off, red 

 orchil results; afterward the plants are dried and ground to a fine 

 powder. 



The French employed a crustaceous species commonly called 

 "perelle" to obtain a purple-blue dye. M. Cocq, in the eighty-first 

 volume of the Annales de Chimie, describes its preparation as observed 

 at Clermont, France. The lichen was macerated in wooden troughs, 

 6 by 3 by 2 feet, and fitted with tight covers. Two hundred pounds of 

 perelle and 240 pounds of urine were mixed in the trough and stirred 

 every 3 hours for two successive days and nights, care being taken to 

 keep the covers closed to avoid loss of the volatile alkali (ammonia). 

 On the third day, 10 pounds of sifted, slaked lime were added and 

 well mixed with a quarter-pound of arsenic and an equal weight of 

 alum. The mass was then stirred several times, once every quarter- 

 hour, later every half-hour, until fermentation was established, to 

 prevent the formation of a crust on the surface of the mass. Fer- 

 mentation was renewed by adding 2 pounds of sifted lime, and stirring 

 once every hour for 5 days. On the eighth day it was stirred every 6 

 hours, and the processing might extend a fortnight to 3 weeks. The 

 coloring matter was kept moist in closed casks until used. It was said 

 to improve the first year, to suffer little change during the second year, 

 and to begin to deteriorate in quality during the third year of storage. 



Bancroft recommended the use of ammonia instead of urine, and of 

 hogsheads to facilitate agitation ; the addition of arsenic and alum he 



