184 LECTURE XVt. 



tion is encouraged in this country by a bounty from government, and a large 

 quantity is also imported from the north of Europe. The plant, while green, 

 is laid in water for ten days, and undergoes a chemical cliange, Avhich softens 

 the pulpy part, without injuring the strength of the fibres, and renders it 

 more easy, when it has been dried and exposed to the air for a fortnight, to 

 separate the two substances in the process of dressing it. This is performed 

 by beating it with the edge of a flat piece of wood, the stroke being oblique, 

 and nearly in the direction of the fibres, and afterwards combing it, in order 

 to reduce the fibres into regular order, and to prepare them for spinning. The 

 refuse, consisting of the shorter fibres, is tow. 



Cotton is a fine fibrous substance, that envelopes the seeds of a plant. The 

 best is brought from the isle of Bourbon ; but by far the greatest quantity 

 from the West Indies, although the Turkish dominions as well as the East 

 Indies furnish us with a considerable supply. It is usually white, but there 

 is a yellow kind, which is used for nankeens. It is separated from the seeds 

 by means of rollers, between which it passes, and leaves the seeds behind. It 

 is then beaten, on a flake, or a stool covered with a texture of cord. Next, it 

 is carded, either by hand, the fibres being drawn into regular order by cards, 

 that is, by brushes of fine pointed wire ; or, more commonly, by machinery, 

 the cards being disposed in cylinders which revolve nearly in contact with 

 each other. The drawing or roving machine then draws it into long flakes, 

 a state preparatory to its being spun by Sir Richard Arkwright's machines or 

 jennies, which form at once forty thteads by the labour of one person. 



. The silkworm is bred in the greatest abundance in Italy and in Asia; it has 



lately been introduced very successfully into the British possessions in the 



East Indies. The principal food of the caterpillar is the white mulberry tree, 



which is too delicate to thrive well in northern climates : in Italy the trees 



are planted in beds, like willows, and the foliage is cut as it is wanted. The 



room in which the Avorms are fed, is kept at the temperature of 80 degrees of 



Fahrenheit. The eggs of a former year are hatched either by animal heat, or 



by that of the sun ; at the age of six weeks, the caterpillars begin to spin, 



first a light external texture, which is carded and spun for coarse silk, and 



afterwards a compact oval pod or cocoon, of one continued thread. The 



threads of several cocoons are reeled off at the same time ; for this purpose 



