Page:The history of silk, cotton, linen, wool, and other fibrous substances 2.djvu/132

 CHAPTER VII.

DESCRIPTION OF THE SILK-WORM, &c.

Preliminary observations—The silk-worm—Various changes of the silk-worm—Its superiority above other worms—Beautiful verses on the May-fly, illustrative of the shortness of human life—Transformations of the silk-worm—Its small desire of locomotion—First sickness of the worm—Manner of casting its Exuviæ—Sometimes cannot be fully accomplished—Consequent death of the insect—Second, third, and fourth sickness of the worm—Its disgust for food—Material of which silk is formed—Mode of its secretion—Manner of unwinding the filaments—Floss-silk—Cocoon—Its imperviousness to moisture—Effect of the filaments breaking during the formation of the cocoon—Mr. Robinet's curious calculation on the movements made by a silk-worm in the formation of a cocoon—Cowper's beautiful lines on the silk-worm—Periods in which its various progressions are effected in different climates—Effects of sudden transitions from heat to cold—The worm's appetite sharpened by increased temperature—Shortens its existence—Various experiments in artificial heating—Modes of artificial heating—Singular estimate of Count Dandolo—Astonishing increase of the worm—Its brief existence in the moth state—Formation of silk—The silken filament formed in the worm before its expulsion—Erroneous opinions entertained by writers on this subject—The silk-worm's Will.

It can never be too strongly impressed upon a mind anxious for the acquisition of knowledge, that the commonest things by which we are surrounded are deserving of minute and careful attention. The most profound investigations of Philosophy are necessarily connected with the ordinary circumstances of our being, and of the world in which our every-day life is spent. With regard to our own existence, the pulsation of the heart, the act of respiration, the voluntary movement of our limbs, the condition of sleep, are among the most ordinary operations of our nature; and yet how long were the wisest of men struggling with dark and bewildering speculations before they could offer anything like a satisfactory solution of these phenomena, and how far are we still from an accurate and complete knowledge of them! The science of Meteorology, which attempts to explain to us the philosophy of matters constantly before our eyes, as dew, mist, and rain, is dependent for its illustrations upon a knowledge of the most complicated facts, such as the