CHAPTER VII. 
CHOKING THE CHRYSALIS. 
In most silk-producing countries the parties who raise the cocoons sell 
them to the reeling establishments before suffocation is necessary, as 
these establishments have better facilities for this work than are to 
be found in private families. If, however, the reeling is done by the 
raiser, or some time must elapse before the cocoons can be sent to a 
reeling establishment, some means must be used to kill the contained 
chrysalis before the cocoon is injured for reeling purposes by the egress 
of the moth. This can be done by stifling them with steam or choking 
them by dry heat. Steaming is the surest, quickest, and best method, 
if the facilities are at hand; it can be done at any steam mill. The co- 
coons are laid upon shelves in a tightly-sealed box and the steam is 
turned in. Twenty minutes will suffice to do the required work, and 
the cocoons are then dried in the sun. 
The following apparatus has been used by Mr. Walker at the De- 
partment: 
It consists of a tin reservoir, about 
one-third filled with water. Slightly 
above the surface of the water is a 
movable perforated partition, B, in- 
tended to prevent spattering during 
ebullition. The upper portion con- 
tains a perforated pan for holding the 
cocoons, while all is tightly closed by 
a cover. Cocoons may be thoroughly 
stifled by exposure in this apparatus, 
over boiling water, for twenty minutes. 
Tt will be seen, too, that much the 
Same apparatus may be contrived by 
the use of a deep kettle, into which is 
set an ordinary colander full of eo- 
coons. It is well to avoid, however, 
So filling the kettle with water that it 
will splash upon the cocoons in boiling, 
as they should only be subjected to 
: Fic. 28.—Simple stifling apparatus. 
the action of steam. The apparatus is 12 inches in diameter and 13 
Inches deep, and will stifle from 3 to 4 pounds of cocoons at a time. 
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