60 ROMANCE OF LOW LIFE AMONGST PLANTS. 



lichen into a pulp with water, adding thereto an am- 

 moniacal liquid, chiefly gas-liquor, although another 

 kind of ammoniated liquid was largely collected and 

 employed, even within our own experience. The 

 mass was macerated in a moderately warm place for 

 various periods, from a few days to several weeks. 

 By this means a kind of fermentation was induced, 

 and at the end of the process a beautiful purplish 

 compound was produced, possessing a peculiar ammo- 

 niacal odour. 



A testing process may be adopted in a small way 

 by macerating fragments of lichen in a vial containing 

 liquid ammonia, or common hartshorn and water, and 

 shaking them together. If any of the colouring 

 matter be present, the liquor will soon acquire a 

 reddish tint, which, by standing longer, will become 

 of a rich purple. 



In some parts of Scotland there still remain, not 

 only the tradition, but the practice of domestic dying 

 with the " crottles." Formerly a cudbear manufac- 

 tory flourished at Leith and Glasgow, which is now 

 extinct, and then large quantities of Lecajiora tartarea 

 were collected by the peasantry of the western high- 

 lands and islands. Dr. Lindsay says that " in Scot- 

 land, not many years ago, particularly in certain 

 districts, almost every farm and cotterhouse had its 

 tank or barrel of ' graith,' or putrid urine (which was 

 the form of ammoniacal liquor employed), and its 

 ' lit-pig,' wherein the mistress of the household mace- 

 rated some familiar ' crottle ' (the Scotch vernacular 

 for the dye-lichens in general), and prepared there- 

 from a reddish or purplish dye." 



