1882.] 
Silks and Silkworms, 
83 
incapable of spontaneous decomposition. Rags of silk 
buried in the earth, or placed in dung-hills in contact with 
putrefying matter, animal and vegetable, remain unchanged. 
It is, further, less easily soiled than linen, cotton, or wool, 
since dirt does not so readily adhere to its polished surface. 
In all probability, from the same reason and from the wire- 
like structure of its fibre, it must be less liable to receive 
and transmit infectious matter than are other textile mate- 
rials. All these properties of silk mark it out as peculiarly 
adapted for human clothing, independent of its lustre and 
of the beautiful basis which it presents for the finest dyes. 
But all are sacrificed by the process of weighting. The 
silks are alternately steeped in decoCtions of catechu and 
logwood, and in solutions of iron — the so-called rouille of 
the Lyon dyers. In addition come solutions of potassium 
ferrocyanide, for the purpose of depositing a quantity of 
Prussian blue upon the fibre and counteracting the brownish 
tint communicated by the other ingredients. At last, after 
a number of operations, sometimes exceeding twenty, the 
dyer succeeds in converting the original pound of silk into 
three pounds of something ! That his task is difficult and 
delicate there is no denying. But so is that of the forger, 
who, in spite of all the elaborately engraved and coloured 
grounds till lately in use, succeeds in altering the figures and 
words expressing the real amount of a cheque, and in sub- 
stituting others. But our admiration for his skill and 
knowledge does not blind us to the criminal character of his 
purpose. We do not see that the “ loading” and “ weighting” 
dyer should fare any better, though he is merely the cat’s- 
paw of the manufacturer or the merchant. For what has 
he effected ? He has rendered the permanent, almost in- 
combustible silk not merely inflammable on contact with a 
match or a lighted candle, but capable of destruction by 
eremacausis, and even of downright spontaneous combus- 
tion, endangering goods trains, ships, and warehouses. Here 
surely is a laughable instance of human folly. We try, ear- 
nestly and perseveringly, to find out some method of rendering 
cotton and linen tissues uninflammable ; but when Nature 
kindly gives us a material free from this danger, we work in 
the opposite direction, and do not rest till we have rendered 
it not merely liable to ignition, but even spontaneously com- 
bustible. The very same treatment renders the silk a much 
better conductor of heat and electricity, reduces its power of 
supporting a weight or strain, and of resisting friction. Its 
surface on microscopic examination is no longer smooth and 
glassy, but rough. Hence it readily takes up dirt, and is 
