THE TORTOISESHELL OF COMMERCE. 381 



is of two colours ; the portion attached to the upper shell partaking of its 

 mottled colouring ; the portion attached to the lower shell being of the 

 bright yellow, even colour of the belly-shell. This latter is principally used 

 for the same purpose as the gold-coloured portion of the hoof. The imports 

 of both these kinds are trifling, amounting to about two tons per annum, 

 and the value from 8s. to 18s. per pound. 



The mode of working tortoiseshell being very interesting, and but little 

 known, the following account, taken from MM. Dumeril and Bibron's 

 ' Epetologie Generale,' may not be unacceptable : 



" The substance of the scale, considered as rough material, is unfortu- 

 nately brittle and liable to split : on the other hand, it possesses most valu- 

 able properties. The fineness of its texture, its compactness, the admirable 

 polish and the carving which it is capable of receiving, the facility with 

 which it may be moulded, its fragments soldered together, melted or amal- 

 gamated by the aid of powder of the same material — these qualities give to 

 it its value. The scales of the turtle in question, when detached from the 

 carapace, are bent in different ways ; their thickness, besides, is not 

 uniform, and often it happens that they are too thin, at least throughout a 

 great portion of their substance. 



" In order to straighten them, it is sufficient to steep them in boiling 

 water for a few minutes, and then take them out and place them between 

 plates of metal or smooth blocks of hard wood, leaving them to cool, great 

 pressure being applied at the same time. They then retain the flatness 

 desired. They are next scraped and filed, a smooth surface being obtained 

 with as little loss as possible. When these shells or scales are brought to a 

 proper thickness and size, they may be then used separately, but they are 

 generally submitted to a still further preparation. When, for instance, they 

 are too thin, or when they are not sufficiently long or broad, the following 

 processes are employed : — In order to obtain single plates of great size, two 

 are soldered together, the thin part of one being laid upon the thin part of 

 the other ; or, as is sometimes done, the edges of each plate are delicately 

 bevelled and fitted together. In each case they are then put between 

 metallic plates ; to these a certain degree of pressure is given, which, when 

 the whole is plunged into boiling water, is increased, and by this mode they 

 are so intimately joined together that the slightest trace of their union 

 cannot be detected. 



" It is almost exclusively by means of boiling water that the effects upon 

 tortoiseshell are obtained. The substance of the scales becomes so softened 

 by the action of the heat, that it may be acted upon like a soft mass, or a 

 flexible and ductile paste, which by pressure in metallic moulds will assume 

 every variety of form required. 



" The soldering of two pieces together is effected by means of hot 

 pincers, which, while they compress, at the same time soften the opposed 

 edges of each piece, and amalgamate them into one. No portion of the 

 scales is worthless : the raspings and powder produced by the file, mixed 

 with small fragments, are put into moulds, and subjected to the action of 



