954 



COTTON 



Corundum, or Corone, is the Indian name for the mineral called also Adamantine 

 spar. The Chinese specimens have a grey colour, but the variety from India is 

 whiter. The extreme hardness of this substance, scratching everything except diamond, 

 renders it remarkably valuable to lapidaries and seal-cutters. It is but little softer 

 than the ruby, sapphire, or oriental topaz. It is far superior to emery for grinding, 

 and is used throughout India and China for polishing stones, &c. Large deposits of 

 crystalline corundum have recently been discovered in North Carolina, U.S., and have 

 been worked commercially, especially at Corundum Hill, in Macon Co. The corundum 

 occurs in veins running through serpentine, and is associated with ripidolite, jeffere- 

 site, &c. 



COSTEA.BTXXTG, a mining term, from the old Cornish Cothas stean, fallen or 

 dropped tin. It signifies the practice of sinking pits in search of lodes across the line 

 of direction which the tin lodes usually traverse in Cornwall. 



COTTON is a vegetable fibre covering the entire surface of the seeds of species of 

 Gossypium plants which belong to the natural order Malvaceae. Cotton is unlike any 

 other textile fibre used in commerce in the fact that it is a hair formed of a single 

 cell. In the vegetable world there is an almost endless series of cell-forms, marked 

 by the two extremes of a perfectly spherical cell, and of a cell so attenuated as to 

 be nearly cylindrical. The latter form is characteristic of cotton. In its early stage, 

 the cotton hair consists of a hollow tube, a transverse section of which would present 

 an elliptical outline ; but in the course of growth, partly from the pressure of contiguous 

 hairs, and partly from a loss of moisture, the cylinder collapses and becomes tape-like 

 in form. The collapse is not uniform, however ; all down the centre of the hair the 

 rides are parallel, but at each edge a ridge is formed by the folding of the cell-walls. 

 The hair thus comes to have the form of an ordinary railway rail, and its transverse 

 section presents the general appearance of a dumb-bell. The two rounded edges of the 

 hair have, however, a tendency to twist upon themselves, and give to it a certain curly 

 roughness. It is this characteristic of cotton which makes it especially valuable for 

 spinning purposes ; the corrugations of the surface helping to bind the fibres together, 

 and to give strength and elasticity to the thread. 



Many other vegetable hairs have been tried as substitutes for cotton, such as the 

 ' cotton grass,' (Eriopkorum) often seen upon bogs and moors, but they have all failed, 

 because they are not formed of a single hair, but of a linear series of hairs united by 

 their extremities. In all such cases the points of union of the several cells form knots 

 in the fibre which render the hairs liable to entanglement and severance when acted 

 upon by machinery. Other substitutes for cotton, which have resembled it in being 

 uni -cellular, have nevertheless failed from being too short. 



The fibre of cotton is the longest uni-cellular hair known in the vegetable kingdom, 

 and its length varies with the species, or according to the locality in which it is grown. 

 It is this variability in the length of the fibre in commercial language its ' staple ' 

 which is the most important factor in determining the price ; the longer the staple 

 the more it is worth. The description of cotton which has the longest staple.is known 

 as Sea Island, the average length being 1'61 inch; Egyptian stands next, with a 

 fibre of 1-41 inch; then Peruvian, 1'30 inch; Brazilian, 1'17 inch; New Orleans, 

 T02 inch ; and finally Indigenous East Indian, 0'89 inch of average length. 



Comparatively little attention has yet been directed (and that only within recent 

 years), to the improvement of the essential qualities of cotton fibre. And it may be 

 assorted that a wide field lies yet before the cultivator for the adoption of such methods 

 of irrigation, manuring, hybridisation, and general treatment as will lead to future 

 developmental of those qualities, and to an enlarged production of the plant. The 

 enormous changes which modern agriculturists have brought about by the treatment, 

 on scientific principles, of cereals and root crops are probably not more marvellous than 

 those which another generation may see, with duo care and method, in the culture of 

 cotton. Cultivators have got to discover, from careful analysis, what materials they 

 can add to the soil to increase the strength, length, whiteness, and lustre of the hair ; 



