of finishing I should not be surprised if difficulty were found in
getting a high degree of lustre and finish upon hairs thus roughened or
partially disintegrated. Figs. 11 and 12 respectively illustrate fur
fibres from different parts of the same hare before and after the
treatment. In examining one of these fibres from the side of a hare, you
see what the cause of this roughness is, and what is also the cause of
the difficulty in giving a polish or finish. The free edges are
partially disintegrated, etched as it were, besides being caused to
stand out. A weaker acid ought to be used, or more mercury and less
acid. As we shall afterwards see, another dangerous agent, if not
carefully used, is bichrome (bichromate of potassium), which is also
liable to roughen and injure the fibre, and thus interfere with the
final production of a good finish.




LECTURE II

TEXTILE FIBRES, PRINCIPALLY WOOL, FUR, AND HAIR--_Continued_


With regard to the preparation of fur by acid mixtures for felting,
mentioned in the last lecture, I will tell you what I think I should
recommend. In all wool and fur there is a certain amount of grease, and
this may vary in different parts of the material. Where there is most,
however, the acid, nitric acid, or nitric acid solution of nitrate of
mercury, will wet, and so act on the fur, least. But the action ought to
be uniform, and I feel sure it cannot be until the grease is removed. I
should therefore first wash the felts on the fur side with a weak