336 
ON THE PRODUCTION OF 
wisli to make a selection of cocoons for grain amongst 
his productions intended for silk spinning, ought to be 
prepared to find the following year not only that his 
hopes of a fine crop are not realised, but perhaps have 
ended in total disappointment. Education under heat, 
however necessary for obtaining a crop of silk in a 
short time, is an unnatural process, which infallibly 
engenders the principles of disease in the silkworm. 
Besides, the merest elementary data of a rational 
selection will easily lead anyone to believe the fact. 
The magnanerie is a large shed, of good height, open 
on all sides, having the two sloping surfaces of the roof 
pierced with ventilating chimneys. The enclosing 
panels are entirely made of wire-gauze. Folding 
frames are used, with blinds stretched over them, that 
they may be let down when the sun's rays fall directly 
on the silkworms, or when the wind is too strong. 
These blinds are to be lowered only when absolutely 
necessary; in ordinary weather they remain open day and 
night, fixed by an iron hook to the ceiling. The roof 
must be lined with planking, to prevent the possibility 
of rain coming through, or the insects which may lodge 
in the interstices of the slates. It is of such a slope 
as will favour the free circulation of air, and pierced at 
intervals of two metres (six feet), with ventilating air 
holes, each capped with a tin tube, the orifice of which 
is covered with wire gauze. The floor, raised about six 
inches above the level of the ground, is to be covered 
with tiles or cement. The wire gauze, having twenty 
threads to the inch, nailed on the wooden cross-pieces 
and uprights which support the roof, is to extend from 
the ground to the eaves, which project beyond the 
walls about twelve inches, and are fitted with spouts 
