At present it is sufficient to notice the discovery that has been made, and to welcome another instance of the results of scientific labour being for the advantage of manufacturers.

SILK′WORM, Diseases of. Silkworms are liable to a disease known as pébrine, which Pasteur has shown to be due to the presence, on the body, the egg, and in the blood of the insect, of peculiar parasitic corpuscles.

Pasteur states that the black specks which constitute these bodies are very easily distinguishable in the moth of the silkworm, but that in the earlier stages of its development, such as in the egg and worm condition, the detection of them becomes difficult, if not impossible. Pasteur further adds that sound moths produce sound eggs, and unsound moths the reverse, and that although the unsound eggs show no sign of disease, they never give rise to healthy worms.

Pasteur advises the silk cultivator, therefore, to ensure breeding from healthy moths at starting, and to abandon the old and useless precaution of hatching apparently healthy eggs.

The loss resulting from the silkworm disease in Italy may be seen from the following tables, which are calculated for bales of 102 lbs. weight:[163]—

[163] ‘British Manufactory of Industries,’ Stamford.

Average production prior to disease, 81,600.

1863Bales,50,600Deficit,38per cent.
1864”38,000”53”
1865”38,700”52”
1866”39,600”51”
1867”44,000”46”
1868”41,000”49”
1869”47,300”42”
1870”69,900”14”
1871”76,300”6”
1872”68,000”16”

The value of the cocoons grown in the whole

world in 1870 was said to be as follows:—France, £4,334,000; Italy, £11,260,000; Spain and other European countries, £984,000; giving a total for Europe of £16,588,000. China, £17,000,000; India, £4,800,000; Japan, £3,200,000; Persia, £920,000; other Asiatic states, £2,192,000; giving a total for Asia of £28,112,000. Africa, £68,000. America, £20,000. Making a general total of £44,788,000.