adhere to the cloth by a silky gummy substance. The temperature is now brought down to 66°, and when the colour of the ova has changed to ash-colour, the cloth stretched on a frame may be removed to a cool apartment, where the eggs should be kept dry. When the eggs are required, they are detached by immersing the cloth in fresh water, which dissolves the mucilage. The ova arc then dried with care.
The uncoiling of the silk from the cocoons is effect ed by collecting the ends of the threads, and winding them on reels, the greatest care being taken that the uncoiling goes on freely through all the extent of the cocoon. This effect is promoted by throwing them into caldrons of water nearly boiling. The threads are then collected by a whisk or brush, and passing through plates of steel they are wound upon a reel by machinery, attached to a water wheel, or any other power.
" Gensoul of Italy," says Mr. Murray, '' has in vented an apparatus by means of which the water is heated through the medium of steam, and the nym phx that fall are collected on a grating of iron wire at the bottom of the boilers, which is frequently raised for the purpose of removing the husks. By this in genious method much fuel is saved, one furnace with its boiler serving to heat twenty vessels, and from the decreased temperature the cocoons do not suffer any decomposition or change, as is the case in the ordi nary way wherein they are immediately exposed to the direct agency of the fire. Another saving might still be effected by this method, in the substitution of vessels or cisterns of wood for boilers of copper. In the month of August last, at Buffalora, on the Mi lanese frontier, I visited an establishment for unwind ing the silk. Women were arranged in two rooms, opposite each other, and conducted the process. The cocoons contained in baskets on one side were thrown by handfuls into caldrons of water, kept boiling by charcoal fires beneath. Each by a whisk (of peeled birch) collected the threads en masse, the first con fused portions were rejected, till the threads unwound regularl), freely passing over glass-rods to prevent the injuries of friction. The first portions are neces sarily useless, and are separated by the hand. When the threads came off uniformly, the cocoons were rais ed suspended to the baud by their respective threads, and thus handed over to those on the opposite side, who, in their turn, threw them into caldrons of water, the temperature of which was nearly that of blood heat, and more than milk warm—thus sustained by a steam pipe. The water was thus kept clear, and the silk preserved pure and unsoiled. From these the threads were finally wound. The proprietor inform ed me that this establishment cost 60,000 francs." The following tables, containing a general view of the process carried on, and the results obtained by Count Dandolo, were abridged by Mr. John Murray from Count Dandolo's work, and first published in Dr. Brewster's Journal of Science, No. III, p. 59, Jan.
The external temperature was ascertained at five o'clock, every morning, from a western exposure.
During the thirteen clays in which the silk-worms were developed from the ova, 134 lbs. of food were consumed. The lb. of 28 ounces is to be understood, or 2 lbs. Troy equivalent to 0.7625 kilogrammes of France.
So that the 1000 ounces have lost in 10 clays, dur ing the mutation, 75 ounces. There is a gradual de clension for the first five days inclusive, and a regular gradation for the last five days.
Each grain contains about 68 ova, and an ounce weight 39,168 ova. The oneia Milanese contains 575 grains. The above number is to be understood of fecundated ova. Those which are badly impregnated contain 43,080, and are of a reddish colour; and of those not at all impregnated, and of a yellowish tinge, there are in the ounce 44,100.
Lira Milanese is equal to about 8d. and there tz 0 So/di in a Lira M.
The calculation, as above, includes not only interest on capital, but a valuation on the mulberry leaves, which is about one-hall' of the total expense.
Note.—In 30 days the silk-worm has increased in weight 9500 times; and, in 28 days, the animal has augmented in size about 40 times.
The French Line is equal to 1.67 Lines English, calculated 100 Lines English to the inch.
In the space of about 23 days more, the silk-worm has diminished in weight about 30 times. Thus, the length of the silk-worm from the time of its greatest increase to the moment it is converted into the chry salis, has diminished about three-fifths. The chrysa lis is the intermediate state between the caterpillar and the winged insect. The larva emerges from the ova, spins its cocoon or domitory, and therein passes into the state of the pupa. It finally emerges from thence the imago, or winged insect, which dies so soon as the ova are deposited.
Note.--The Braeeio di Milano is divided into 12 ounces or inches, and corresponds to 5.95 palms, which may be calculated at 22 English inches nearly.
In the course of the management of the silk-worms, the 1073 lbs. of leaves from the tree (from evapora tion, and other causes) will have lost 70 lbs.
/Vote.—There have been devoured by the silk-worm about 515 lbs. of pure mulberry leaves. The 10731113. of leaves as taken from the tree will yield 80 lbs. of cocoons, calculating from one ounce of ora.
The artificial heat necessary in Count l)andolo's process, is kept up by a stove of tile, those of iron being injurious. The necessary dryness of the air may be produced by absorbent substances, and when it is too dry, shallow vessels of water are placed on the floor.
For farther information on this subject, see Reati mur, Mem. .dead. Par. 1710. Aglionby, Phil. Trans. 1699, vol. xxi. p. 183. Bon, Id. Id. 1710, vol. xxvii. p. 2. Daubenton, Mem. .4cad. Par. 1779, p. 1, 1785, p. 45. Rev. U. Swayne, Transactions of the Society of arts, vol. vii. p. 123, 148. Dr. Anderson's Bee, No. 72, 95, 156. Dr. Anderson on the Culture of Raw Silk on the Coast of Coromandel. Transactions of the .qinerican Philosophical Society, vol. ii. Count Dan dolo, Bell' dile di Goccrnare i Bachi da Seta 2 da. Ediz. 'Niihau°, 1818. Murray, in Dr. Brewster's Journal of Science, No. III. p. 59; and 'Murray's Re marks on the Cultivation of the Silk Worm, with .1ddi liana!, Observations made in Italy during the ,Yumincr of 1825, Glasgow, 1825. An Account of the Histo ry, Value, and Present State of the Silk Manufacture in England will be found in our article ENGLANE.— or France, in our article FRANCE.—in /My, in the ar ticle ITALv.—and in India, in our article Isola.