« AnteriorContinuar »
THE SILK CULTURE.
Silk in FLORIDA.—The Tallahassee Floridian of the 15th inst., says:
“We have been presented with a specimen of sewing silk, raised and manufactured by a daughter of Major Lee, at his plantation on the Armonia. The sample consists of some two dozen skeins of a variety of colors, and in quality it is pronounced by competent judges equal to any brought to this place.”
So great is the progress in the northern and eastern States of this most important branch of culture, that our friends the Messrs. Prince and Sons, of Flushing. L. I., on Thursday concluded the sale, to one company alone, amounting to sixty-five thousand dol. lars, for that invaluable food for the silk-worm, the Morus Multicaulis mulberry tree, now grown in such perfection in their beautiful and extensive gardens.
Important Invention. There has lately been invented and is now in successful operation in the family of a respected member of the Society of Friends, in Rhode Island, a very simple machine by which the silk is by one operation reeled directly from the cocoons into sewing silk and silk twist of a very superior quality, and suitable for immediate use.
Raw silk is now produced in Connecticut at a cost of $150 per pound, for which the producer receives a bounty from the State of $1 50, and sells the silk readily at $6 a pound, making a clear gain therefore of that sum for every pound, and the demand is greater than the supply.
Ought not our own State to foster also our citizens by offering similar encouragement to this most important culture. The silkworm flourishes in our country to a perfection and extent unknown, we believe, in any other. As an instance we may cite that at the establishment of the Hon. Ambrose Spencer, near Albany, out of one lot of 40,000 silk-worms hatched during the present season, but four were lost. By preserving the eggs in a cool place, a cellar, or well, or ice-house, of a permanent temperature, they can be taken out any time and hatched whenever the worm is wanted.
N. Y. Star.
WOOL Notwithstanding the great dissimilarity in appearance, chemical examination has made it certain that the nails, hoofs, horns, hair, and wool of animals is substantially of the same substance and nature; and the texture and hardness of the skin of animals, as exemplified in what is termed raw hide, proves that this also is separated
from the others by very slight shades of difference. That the horn of the ox is made up of elongated fibres or hairs, is obvious to every one as they can be clearly traced in the structure; that it is so in those of other animals is probable from the examination of those of the deer and giraffe in which the hairs can be traced into the covering of the horn; and from the fact, that the horns partake in a greater or less degree of the nature of the hairy or wooly covering, being smooth, or curled and wavering, in almost exact proportion as these are so. To be convinced of this, it is only necessary to compare the horn of the hairy or long wooled animals, such as the Angora goat or the wild sheep of the Rocky mountains, with fine wooled, or silken haired ones, as the Saxon or Merino sheep. The straight or wavy appearance of the first kind of horns, and the short curls and sweeping curves of the last will be at once apparent.
Wool derives its greatest value from the quality of felting which it possesses in a degree superior to almost any other substance. Owing to this quality, wool can be rapidly formed into cloth, and when subjoined to the process of fulling as it is termed, the cloth can be rendered of any desirable thickness. This quality is owing to such a conformation of the fibre as to allow them to slide freely over one another in one direction, while in the other, they cannot move at all. This property may be perceived at once in a common hair, which, placed between the fingers, and these slipped upon it, invariably moves in one direction, always advancing in the direction of the root of the hair, and the same is the case with the fibre of wool. Had wool been destitute of the felting quality, it might indeed have been made into cloths, as silk, linen, and cotton now are, but the property of thickening by any operation subsequent to weaving would have been wanting, and it would have been inapplicable to a multitude of purposes in the arts to which it now seems indispensable.
The particular formation of the fibre of hair of wool that gave them this peculiar quality of felting, (and some wools possess this property in a far greater degree than others,) has given rise to much speculation, and been the subject of much microscopic investigation. M. Monge, a French chemist, well known for his scientific researches and discoveries, was one of the first to advance a correct opinion on the subject; and he appears to have arrived at the result more from reasoning on what must be the actual structure of wool to possess its well known qualities, than from any superior facility for observation. He asserted, “that the surface of each fibre of wool is formed of lamellæ, or little plates which cover each other from the root to the point, pretty much in the same manner as the scales of a fish cover that animal from the head to the tail, or like rows placed over one another, as is observed in the structure of horns;" and he accounts for the felting process in the following way:
"In making a felt which is to constitute the body of a hat, the
workman presses the mass with his hands, moving them backwards and forwards in various directions. This pressure brings the hairs or fibres against each other, and multiplies their points of contact. The agitation gives to each hair a progressive motion towards the root; but the roots are disposed in different directions-in every direction; and the lamellæ of one hair will fix themselves on those of another hair, which happens to be directed a contrary way, and the hairs become twisted together, and the mass assumes the compact form wbich it was the aim of the workman to produce. *
* * * If the wool is in cloth and subjected to the process of felting, the hairs which compose one of the threads, whether of the warp or the wool, assume a progressive movement; they introduce themselves among those of the threads nearest to them, and thus by degrees all the threads become felted together, the cloth is shortened in all its dimensions, and partakes both of the nature of cloth and felt.”
The great improvement which within a few years has taken place in the construction and application of the microscope, has reduced to a certainty what with the French philosopher was only a probable deduction. It has shown that the hair, wool, or fur, of animals differs very remarkably in its appearance, and consequently in its adaptation to useful or manufacturing purposes. Mr. Youatt, of London, was the first to demonstrate satisfactorily that wool possessed the laminated form ascribed to it by M. Monge. A fibre of Merino wool was submitted to a microscopic power of 300 (linear,) the instrument by Mr. Powell, and the appearance is thus described by Mr. Youatt:
“The fibre thus looked at assumed a flattened riband-like form. It was of a pearly grey color, darker towards the centre, and with faint lines across it. The cdges were evidently hooked, or more properly, serrated—they resembled the teeth of a fine saw. They were somewhat irregular in different parts of the field in view, both as to size and number. The area of the field was now ascertained; it was one-fortieth of an inch in diameter. * * * By means of the micrometer the number of serrations in an inch was ascertains ed and found to be 2400. Its actual diameter was proved to be the 750ih part of an inch.”
Though the lamellæ was not so distinct on the Merino fibre as on that of the bat, yet the cone-like points were distinctly visible; forming a series of cup-like indentations, with their projecting edges pointing from the root to the point.
A fibre of Saxon wool was next subjected to observation. It was evidently finer than the Merino, being only one 840th part of an inch in diameter. The serrations are as distinct, but more nu. merous, being 2720 in an inch. The greater number of serrations, with equal prominence when compared with Merino, accounts for its superior qualities in felting.
The fibre of the South Down, when examined in the same in. strument presented, according to Mr. Youatt, the following appear
inch in diameter. The serrations differ in character; they are larger, but they are not so acute, they almost appear as if they had been rounded; they have a rhomboidal, and not a hooked character, and they are evidently fewer in number in the same space. There are 2080 serrations in an inch, or 640 less than the Saxon." The South Down is a valuable wool, but its felting power is inferior, and is consequently little used in the manufacture of the finest broadcloths.
The improved Leicester, as the next most valuable wool, was submitted to examination and the character of the serrations were found to agree with its diminished felting powers.
“The fibre was found to be one 500th of an inch in diameter, and the number of serrations were 1860 in the space of an inch. The serrations or lamellæ are superficial, irregular, differently formed in different parts, a few like small spines running along the surface of the fibre, while other prominences were rounded.”
The Merino, Saxon, South Down, and Leicester, comprehending the most valuable of the wools, and the two last being the kinds lately imported into this country to a considerable extent, for the purpose of crossing with the American breeds of the two first; this notice of them, showing their relative fineness and felting qualities, may not be unacceptable or useless. In concluding his microscopical examination of wool, Mr. Youаtt arrives at the following conclusions:
“There can no longer be any doubt with regard to the general outline of the woolly fibre. It consists of a central stem or stalk, probably hollow, or porous, and possessing a semi-transparency not found in the ordinary hair. From this central stalk there springs at different distances, in different breeds of sheep, a circle of leaveshaped projections. In the finer species of wool, these circles seemed at first to be composed of one indented or serrated ring; but when the eye was accustomed to them, this ring was resolvable into scales or leaves. In the larger kinds, the ring was at once resolvable into these scales, or leaves, varying in number, shape and size, and projecting at different angles from the stalk, in the direction of the leaves of vegetables, from the root to the point * *
* The conclusion seems to be legitimate, and indeed inevitable that the shape and position of these lamellæ or leaves, is internally connected with, or in fact, that they give to the wool the power of felting or combination, and regulate the degree in which that powa er is possessed."
We may add here that after a careful series of experiments and exarninations with one of Raspail's excellent Parisian microscopes, we are convinced that Mr. Youatt's pescription and delineations, are in the main correct;—and his conclusions such as are narrated by the facts elicited from observation.
After fineness, the goodness of wool is mainly depending on two qualities, trueness and soundness. Manufacturers have long known
that some wools were very unequal in the fibre, in some places being so fine or attenuated as to break in working, and, therefore, cause much of it to be lost in the several processes of working. The microscope shows that in most wools the fibres are the smallest in the middle, or rather that the outer and inner extremities are the largest, the shrinking in most cases being nearest the root; though in some specimens of wool no such difference of size is perceptible. If several such indentations occur, or if the middle fineness of the fibre is too great, the wool is said to lack trueness, and is a decided fault in the eye of the manufacturer. The cause of this inequality was for a long time not understood, but repeated experiments and observations have shown, that the fibre of the wool
animal, and the temperature to which he is exposed. So exactly does the wool agree in form with the treatment it receives, that Dr. Anderson has termed wool a self registering thermometer, and perhaps the best idea of the manner in which this effect on the fineness of the wool is caused, may be gained by supposing the skin to be a species of plate pierced like a wire drawers, and the size of the wool depending on the orifice through which it is forced. If the animal is in a healthy state, in good order, and kept in a proper temperature, the wool will be of equal trueness, or fineness, whatever may be the kind. When, however, the sheep is in ill health, is very poor in flesh, or exposed to fluctuations of high and low temperature, the wool will be unequal, and of course the value much diminished for the manufacturer.
The food of sheep, or the state in which they are kept, has a very great influence on the qualities of the wool. It was a charge brought against Mr. Bakewell, and reiterated against Mr. Ellman the great improvers of the Leicester and South Downs, and it was. one they did not in the main deny, that the wool was sacrificed to the carcase, or in other words, that the rich pasture and fat state in which these sheep were kept was incompatible with great fineness of fleeces; and Mr. Bakewell, in his examination before the House of Lords, stated that he had no doubt that fine wools might be grown on rich pasture lands, by overstocking them, and preventing them from obtaining more nourishment than they had been occasioned to. The size of the fibre may in part be depending on the abundant supply of yolk' which it receives. Lord Sommerville says, "the wool of our merino sheep after shear time, is hard and coarse to such a degree as to render it impossible to suppose that the same animal could bear wool so opposite in quality compared to that which had been clipped from it in the course of the same season. As the cold weather advances, the fleeces recover their fineness, and softness."
Wool growers are generally aware that the quality as well as the quantity of wool, produced by a sheep, deteriorates with age, and that wool from old sheep is difficult to spin, and injures the ma.