mong the silkworms; and I may mention a few facts
which will give you some conception of the gravity of the injury which it
has inflicted on France alone.

The production of silk has been for centuries an important branch of
industry in Southern France, and in the year 1853 it had attained such a
magnitude that the annual produce of the French sericulture was estimated
to amount to a tenth of that of the whole world, and represented a money-
value of 117,000,000 francs, or nearly five millions sterling. What may
be the sum which would represent the money-value of all the industries
connected with the working up of the raw silk thus produced, is more than
I can pretend to estimate. Suffice it to say, that the city of Lyons is
built upon French silk as much as Manchester was upon American cotton
before the civil war.

Silkworms are liable to many diseases; and, even before 1853, a peculiar
epizootic, frequently accompanied by the appearance of dark spots upon
the skin (whence the name of "Pebrine" which it has received), had been
noted for its mortality. But in the years following 1853 this malady
broke out with such extreme violence, that, in 1858, the silk-crop was
reduced to a third of the amount which it had reached in 1853; and, up
till within the last year or two, it has never attained half the yield of
1853. This means not only that the great number of people engaged in silk
growing are some thirty millions sterling poorer than they might have
been; it means not only that high prices have had to be paid for imported
silkworm eggs, and that, after investing his money in them, in paying for
mulberry-leaves and for attendance, the cultivator has constantly seen
his silkworms perish and himself plunged in ruin; but it means that the
looms of Lyons have lacked employment, and that, for years, enforced
idleness and misery have been the portion of a vast population which, in
former days, was industrious and well-to-do.

In 1858 the gravity of the situation caused the French Academy of
Sciences to appoint Commissioners, of whom a distinguished naturalist, M.
de Quatrefages, was one, to inquire into the nature of this disease, and,
if possible, to devise some means of staying the plague. In reading the
Report[11] made by M. de Quatrefages in 1859, it is exceedingly
interesting to observe that his elaborate study of the Pebrine forced the
conviction upon his mind that, in its mode of occurrence and propagation,
the disease