SILK-WORMS. 283 
many died while rising' on the hedge. The cocoons were 
light. No calcination was to be seen. 
7th. He chose sickly worms ; they were exposed to a high 
temperature, to excite transpiration in them ; and according 
to the common notion, thus to ease them of the disorder of 
calcination, which was supposed to have attacked them. 
The temperature was raised from 88° to 98°. The worms 
did not transpire. Those that were really sick died with- 
out shewing any signs of calcination. The rest went through 
their periods of existence with the greatest regularity. 
8th. Some silk- worms were kept too close, and laid thick 
on the wickers ; they almost all died, but shewed no symp- 
tom of calcination. 
9th. Some silk-worms spontaneously hatched having been 
reared in a fluctuating state of temperature, now raised, and 
then lowered, at each moulting many died ; and out of 
3900 there remained only 2600 at the period of rising, and 
many of these were small and sickly. There were only 
1200 cocoons of good quality in the number. 
Finally, the silk-worms, proceeding from half an ounce of 
eggs produced by motbs supposed to be attacked by cal- 
cination, were reared with the ordinary care, and in the 
prescribed rules ; the whole course of their existence was 
regular, they were fine and healthy until the rising on the 
hedge, and produced perfect cocoons. And M. Dandolo 
made his pupils observe, when they expressed their sur- 
prise at this phenomenon, that the diseases proceeding from 
the seed given by weak and delicate moths, are not to be 
feared as irremediably injurious, neither are they so, except 
when the seed has been carelessly collected, or not well 
preserved. 
The change of nature of the silk-worm, when subject to 
the gattina, (says M. Dandolo,) is a real animal dis- 
ease, incident to the silk-worm, as it would be to any other 
living thing, when exposed to bad food, corrupt air or 
water, ill management, or in any primitive defect in the 
conformation of the vital organs. By gattina is generally 
understood a worm that cannot accomplish the prescribed 
