811 Method employed at Astraean for making 
after which they are immersed several times in a strong 
warm ley, obtained, by boiling, from a strong alkaline 
earth named schora , which is found in great abundance 
in the neighbourhood of Astraean. When the skins have 
been taken from this ley, they are piled up, while warm, 
on each other, and suffered to remain in that state several 
hours; by which means they swell, and become soft. 
They are then left twenty- four hours in a moderately 
strong pickle of common salt, which renders them ex- 
ceedingly white and beautiful, and fit for receiving any 
colour. The colour most usual for these skins is a sea- 
green; but old experienced workmen can dye them blue, 
red, or black, and even make white shagreen. 
For the green colour nothing is necessary but filings of 
copper and sal-ammoniac. Sal-ammoniac is dissolved 
in water till the water is completely saturated ; and the 
shagreen skins, still moist, after being taken from the 
pickle, are washed over with the solution on the ungrain- 
ed flesh side, and when well moistened a thick layer of 
copper filings is strewed over them : the skins are then 
folded double, so that the side covered with the filings is 
innermost. Each skin is then rolled up in a piece of 
felt; the rolls are all ranged together in proper order, 
and they are pressed down in an uniform manner by 
some heavy botlies placed over them, under which they 
remain twenty-four hours. During that period the solu- 
tion of sal-ammoniac dissolves a quantity of the cupreous 
particles sufficient to penetrate the skin and to give it a 
sea-green colour. If the first application be not suffi- 
cient, the process is repeated in the same manner; after 
which the skins are spread out and dried. 
For the blue dye, indigo is used. About two pounds 
of it, reduced to a fine powder, are put into a kettle ; cold 
•water is poured over it, and the mixture is stirred round 
