tack from a species of the ichneumon fly,-a very small insect, which has obtained this name through the benefit it renders to man in the destruction of various hurtful insects, and in which respect it is perhaps equally serviceable with the quadruped whose name it has thus been made to bear, and which demolishes the young of more formidable though less numerous reptiles. These flies assail the cassadaworm in such swarms, that it is affirmed there is not one spot on its back and sides left visibly uncovered by them. Proceeding immediately to drive the stings wherewith they are armed through the skin of the worm, the flies deposit their eggs in the bottoms of the wounds they inflict. During this painful operation, the cassada-worm exhibits all the signs of intense suffering, struggling and writhing, and using every effort to shake off its cruel tormentors.

So soon as the flies have accomplished their object in safely depositing their eggs, they disappear; the worm seems exhausted with its previous efforts, and remains for about an hour in a state of lethargy, from which, however, it then awakes, to feed with renewed avidity.

In about fourteen days after having thus been made the unwilling depositary of these eggs, and during which time the worm increases daily in size, it is seen to be completely covered with a living robe of animalculæ, having a deep brown color, so that no more than the top of its head can be perceived. If the operations of these newlyhatched worms are then carefully examined, it will be seen that each, raising itself upon its hinder extremity, swings its head and body to and fro in every direction, and forms for itself an almost imperceptibly small egg-shaped cocoon, remaining, like the silkworm, in the interior of the ball; making thus, as it were, its own winding-sheet, and seeming born but to die.

These millions upon millions of cocoons, as they are described by M. des Lozières, the formation of which has not occupied a greater space of time than two hours, are placed so closely together that they form a white robe, in which the insect fly-carrier appears elegantly clothed. During this process of decoration the worm remains in a state of torpidity; but no sooner is the robe fully completed, than the wearer seeks to disencumber itself of its guests, and, after efforts of some duration, and which appear greatly to exhaust its frame, succeeds in the endeavor. Its appetite is now gone; it speedily passes to the state of a chrysalis; then becomes a butterfly; and, after giving birth to many hundred eggs, appears thus to have fulfilled the end of its being, and dies.

When about eight days have elapsed from the first formation of the minute cocoons by the larvæ, ichneumon flies issue from these, leaving the fibrous substance pure, beautifully fine, and of a dazzling whiteness. This, without any previous preparation, may be immediately carded and spun. According to the opinion expressed by M. des Lozières, it is greatly superior in every respect to vegetable cotton, while in some particulars it is even preferable to the produce of the silkworm; requiring less of time and trouble for its production, and being greatly more abundant in its produce.

It is now, however, nearly forty years since the observations of M. des Lozières were given to the world, and no attempts have been made to realize the advantages which he promised from the pursuit.

NOTE FF. page 180.

The superior fineness of some Indian muslins, and their quality of retaining, longer than European fabrics, an appearance of excellence, has occasioned a belief that the cotton wool of which they are woven is superior to any known elsewhere: this, however, is so far from being the fact, that no cotton is to be found in India which at all equals in quality the better kinds produced in the United States of America. The excellence of India muslins must be wholly ascribed to the skil fulness and patience of the workmen, as shown in the different processes of spinning and weaving. Their yarn is spun upon the distaff, and it is owing to the dexterous use of the finger and thumb in forming the thread, and to the moisture which it thus imbibes, that its fibres are more perfectly incorporated than they can be through the employment of any mechanical substitutes. The weaving art is pursued to such an extent throughout the peninsula, that, according to Mr. Orme (Historical Fragmen's of the Mogul Empire), "it is difficult, when not near the high road, or a principal town, to find a village in which every man, woman, and child, is not employed in making a piece of cloth." Among the multitudes thus trained from childhood to the pursuit of a simple occupation, it would be surprising if some individuals did not attain the capability of producing superior fabrics. The very fine muslins, which thus attest the proficiency of some of the Indians, and which have been poetically described as "webs of woven wind," are, however, viewed as curiosities even in the country of their production, and are made only in small quantities; so that their use is limited, almost exclusively, to the princes of the land.

NOTE G G. page 206.

It sometimes happens that various branches of occupation in the silk manufacture are carried on under the same roof, by different members of the same family. It once occurred to the author of this treatise, in the course of his visits among the operative weavers in the district of Spitalfields, to visit a family consisting of a man, his wife, and ten children, all of whom, with the exception of the two youngest girls, were engaged in useful employments connected with the silk manufacture.

The father, assisted by one of his sons, was occupied with a machine, such as is mentioned in page 213, punching card slips from figures which another son, a fine intelligent lad about thirteen years of age, was "reading on." Two other lads, somewhat older, were in another apartment, casting, drawing, punching, and attaching to cords the leaden plummets or lingos, which form part of the harness for a Jacquard loom. The mother was engaged in warping silk, with a machine similar to that described by fig. 7. page 155. One of the daughters was similarly employed at another machine, and three other girls were in three separate looms, weaving figured silks, one by the aid of the mechanical draw-boy, described at page 190, the others with Jacquard machines.

An air of order and cheerfulness prevailed throughout this busy establishment that was truly gratifying; and, with the exception of the plummet-drawers, all were clean and neatly clad. The particular occupation wherein each was engaged, was explained most readily,

and with a degree of genuine politeness, which proved, that amid the harassing cares attendant upon daily toils of no ordinary degree, these parents had not been unmindful of their duty, as regarded the cultivation of their children's minds and hearts.

NOTE H H. page 248.

Material substances have generally been divided into two classes, electrics and non-electrics; which distinction, if taken strictly, is not correct there is no positive line of demarcation between the two. There is not any electric or non-conducting substance that is a perfect insulator; neither is there any non-electric or conducting substance that cannot, by friction, be made capable of exhibiting electrical phe

nomena.

INDEX.