416 On the Management of the Silk-ff^orm. 
The Fifth Age, — the 27th dag of rearing. 
This is the commencement of the longest and most dangerous age of 
the Silk-worm, and the greatest attention must be paid not only to the 
feeding, but to the ventilating, to keep up a regular temperature, and 
prevent dampness and noxious air. Strict attention must be paid to 
clean the trays of the excrement of the Worm and the refuse leaves 
every morning; for cleanliness is of the greatest consequence. 
The thermometer should be kept up to 68 degrees, or perhaps va- 
rying from 65 to 75 degrees, but not under 65 if possible. A Hy • 
grometer is a most useful instrument to measure the humidity of the 
apartment, as a dry atmosphere is of great importance, and dampness 
may be considered the greatest bar to success in rearing the Silk-worm 
in this country. If a hygrometer cannot be had, a little salt placed in 
a dish will show when there is any appearance of dampness ; when there 
is the least indication, blazes of wood-shavings, or small wood, should 
be had recourse to, until the dampness disappears ; or if a fire is requi- 
red to maintain a heat as well, billets of wood, or coal, must be used. 
If ventilating and blazing fires are not sufficient to carry off the noxious 
air arising from diseased Worms or other causes, recourse must be had 
to kill it, which may be done with the following ingredients: with 2 oz. 
of salt, mix 1 oz. of powder of black oxyde of manganese ; put this mix- 
ture in a wine bottle, with 2 oz. of water, stir it about, then cork it well, 
until you want to use it; procure also about half-a-pound of sulphuric 
acid. Care must be taken not to place it near the fire. When it is 
required to kill the noxious air, pour a little of the sulphuric acid, — say 
about a tea-spoonful, into the bottle containing the mixture of black 
oxyde of manganese ; a light vapour will issue from it. The bottle 
should be moved up and down the apartment : this should be repeated 
perhaps two or three times a day. The bottle must be well corked when 
not in use. Always when the cork is drawn, hold it as far from you as 
you can, as the vapour is very searching, and rather dangerous: when 
you fumigate, add a little of the sulphuric acid, but not so much as at 
first. Should the substance in the bottle harden, add a little water, and 
stir it about. 
In this last age, the Silk-worms should be fed with full grown leaves, 
and given whole ; the quantity they will require, if they succeed well, 
will be about four times what they consumed the last four ages. They 
must be given perfectly dry, and a stock of leaves should be kept always 
on hand, in case of wet weather. If they are two days old they will 
answer very well, but must be kept dry, a little spread out, and turned 
occasionally, to prevent them from sweating, and the top leaves from 
shrivelling. Up to the sixth day they will consume an immense quantity 
of leaves, increasing the quantity every time you feed. On the morning 
