282 
THE ART OF REARING 
ten following- experiments to try the disorder, and to demon- 
strate the error of his antagonist by clear evidence of truth ? 
1st. He placed the silk-worms of one ounce of eggs in the 
upper story of the establishment, and left them exposed to 
atmospheric variations, which were great that year, until 
they rose on the hedges ; many died, but not one of calcina- 
tion. 
2nd. The silk-worms proceeding from one ounce of eggs 
were put in a small laboratory after the first moulting, and 
reared in it until the fifth day of the fifth moulting, without 
the air being renewed at all in the laboratory : no worm was 
attacked by calcination. 
3rd. In the same laboratory a certain number of worms 
were put into boxes. After the third moulting the air wag 
so corrupt, it contained not above - 3^0 or T&o °f oxygen 
The worms nearly all died, but without presenting the 
slightest symptom of calcination. 
4th. A certain number of worms, after the first moulting, 
were reared at 55° of heat, and were gradually used to the 
temperature. They employed double the usual time in ac- 
complishing their moultings. At the fourth period they 
were only half the weight of the worms raised at the ordinary 
and higher degrees of heat. Although they appeared as 
large, their labour was very unequal, and a part of them 
were attacked by the disease called gattine, which we shall 
hereafter describe. The cocoons weighed one-third less 
than those formed in the usual temperature, but there was not 
a calcined worm in the whole number. 
5th. The silk-worms, reared in 64°, consumed 45 days from 
the hatching, to the fifth moulting or casting of the skin. 
They shewed little vigour ; two-thirds of them perished, 
and they would not have risen on the edge, if the tempera- 
ture had not been raised. The few cocoons they produced 
were of inferior quality, many of these being small and light. 
No worm, however, was attacked by calcination. 
6th. Worms, reared at 66°, consumed 40 days from the 
time of hatching, to the accomplishment of the fifth casting. 
They had no appearance of vigour ; sought warm places j 
