Encyclopaedia Britannica, or, a Dictionary of arts, sciences, and miscellaneous literature : enlarged and improved. Illustrated with nearly six hundred engravings > Volume 19, Scripture-SUG

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hat fitua-
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fayne’s
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il’cribed.
mucli experience in the managing of filk worms, affures
1 -as, that the filk produced from any other food than
mulberry leaves is of an inferior quality, and that the
worms are lickly. We think, however, that there is
reafon to fufpefl that the experiment has not been Ikil-
fully performed ; and therefore, before every other food
except mulberry leaves is difcarded, the experiment
ought ta be performed with more attention and care.
We know that many animals in a domeltic date can live
upon food very different from that which fupported
them when running wild in the fields. Certain it is,
however, that every animal, in its rtate of nature, par-
takes of a food peculiar to itfelf, which is rejected by
other animals .as if it were of a poifonous quality •, and
it may be mentioned as a curious faifl, as well as an ad¬
mirable inftance of the care of that Being who feeds
the fowls of heaven, that notwithflanding the number-
lefs infefts that prey upon animals and vegetables, the
mulberry tree is left untouched by them all, as the ex-
clufive property of the filk worm, the chief of the infedt
tribe, which toils and fpins for the ufe of man.
Having now confidered the food proper for the filk
worm, we fhall next confider what fituation is moll fa¬
vourable to them. In the. opinion of fome perfons in
this country who have been in the practice of rearing
filk worms, they ought always to be kept in a dry place,
well Iheltered, and polfefling a confiderable degree of
warmth, and which is not expofed to fudden tranfitions
from heat to cold. If the weather be too cold, a fmall
fire muft be made : this is of moll importance when the
worms are ready for fpinning. A fouthern expofure
is therefore preferable. Some think light is of great
utility to filk worms, others think that they thrive bet¬
ter in the dark. As to what apartments are bell ac¬
commodated for promoting the health of filk worms,
and molt convenient for thofe who have the care of them,
they may be various according to the extent of the ma-
nufadlure or the wealth of the proprietors. Silk worms
may be kept in boxes or in (helves. When (helves are
to be ufed, they may be conftrudled in the following
manner : The (helves may be of wicker, ranged at the
difiance of a foot and a half, and fixed in the middle of
the room : their breadth ought to be fuch, that any per-
fon can eafily reach to the middle from either fide. This
is perhaps the fimpleft and cheapefi apparatus for rear¬
ing filk worms ; but there is another apparatus which
may be recommended to thofe who are anxious to unite
fome degree of elegance with convenience. This appa¬
ratus is the invention of the Rev. George Swayne of
Puckle-chureh, a gentleman w'ho has ftudied this fub-
je£l much, in order to find out the way for promoting
the culture of "filk among the poor. This apparatus,
with the defcription of it, may be found in the Tranf-
aclions of the Society for encouraging Arts, Manufac¬
tures, and Commerce, vol. vii, p. 148. The apparatus
confifis of a wooden frame four feet two inches high,
each fide 16 inches and a half wide, divided into eight
partitions by fmall pieces of wood which form grooves,
into which the Hides run, and are thus eafily thru!! into
or drawn out of the frame. The upper (lide in the mo¬
del fent to the fociety by Mr Swavne is of paper only,
and defigned to receive the worms as foon as hatched ;
the two next are of catgut, the threads about one-tenth
uf an inch diftant from each other : thefe are for the
mfedls when a little advanced in fize : the five lower
Vol. XIX. Part I.
- (
ones are of wicker work } but, as Mr Swayne afterwards Silk,
found, netting may be fubftituted with advantage in- v”—"v '
(lead of wicker bottoms. Under each of thefe, as well
as under thole of catgut, are Aiders made of paper, to
prevent the dung of the Worms Irom falling on thofe
feeding below them. iS
The management of filk worms is next to be attend-Proper tiroc
ed to. The proper time for hatching them is when thefwr
leaves of the mulberry are full grown, or nearly fo j
that as foon as thefe infedfs are capable of receiving food
they may obtain it in abundance. To attempt to hatch
them fooncr would be hurtful, as the weather would not
be fufiiciently warm. Befides, as leaves are neceffary
to the life of a vegetable, if the young leaves of the
mulberry tree are cropped as foon as they are unfolded,
the tree will be fo much weakened as to be incapable
of producing fo many leaves as it would otherwife have
done ; and if this pra&ice be frequently repeated, will
inevitably be deftroyed. j9
When the proper feafon is arrived, the eggs may be How they
hatched either by the heat of the fun, when it happens ^
to be ftrong enough, or by placing them in a fmall ^ ^
room moderately heated by a (love or fire 5 and after
being expofed for fix or feven days to a gentle heat, the
filk tvorm iffues from the egg in the form of a (mall
black hairy caterpillar. When Mr Swayne’s apparatus
is ufed, the -worms are to b© kept on the drawers with
paper bottoms till they are grown fo large as not rea¬
dily to creep through the gauze-bottomed drawers :
they are then to be placed on thofe drawers, where they
are to remain till their excrements are fo large as not
readily to fall through ; when this is the cafe, they mull
be removed to the drawers with the wicker or netting
bottoms, and fed thereon, till they (how fymptoms of be¬
ing about to fpin. It is fcarcely necefiary to mention,
that the paper Aides beneath the gauze and wicker
drawers are intended to receive the dung, which (liould
be emptied as often as the worms are fed, at lead once
a-day •, or to direft, that when the worms are fed, the
Aides are to be firft drawn out a confiderable way, and
the drawers to reft upon them.
It has been already mentioned, that wet or dampwetor
food is exceedingly prejudicial to thofe infetls. It pro-damp food
duces contagious and fatal difeafes. To prevent the produces
neceflity of giving them wet or damp food, attention
ought to be paid to the weather, fo that when there is
an immediate profpeft of rain, a fufficient quantity of
leaves may be gathered to ferve the worms two or three
days. In this country, the leaves of the black or red
mulberry tree may be preferved good for food, although
kept four or five days, by the following method : When
new gathered, lay them loofely in glazed earthen vef-
fels, place thefe in a-cold place, well aired, not expofed
to drought.
The utmoft attention muft be paid to preferve the Ought to
place where filk worms are kept as clean as poflible : thebe kept as
houfe or room mull be well ventilated, that no noxiousc^ean as
vapours be accumulated. By fome experiments of M.P°®^e'
Faujas de St Fond, which are recorded in his hiftory of
Languedoc, it appears that the filk worm is much injur¬
ed by foul air. All decayed leaves muft be removed
from them, as it is now well known that they emit bad
air in great abundance.
One of the moft difficult branches of the management
of filk worms has hitherto been the cleaning without
Z z bruifing