CONSTITUENTS OF COTTON-FIBRE. 107 



scopCj is found to consist of minute scales and needles 

 suspended in the alcoholic liquid. When the mass is 

 filtered off and dried, it shrinks very much, and is converted 

 into a coherent cake, which has a waxy lustre, is trans- 

 lucent, friable, and lighter than water, and does not soften 

 when kneaded between the fingers. A specimen of the 

 substance from East-Indian cotton, when heated in the 

 usual manner in a capillary tube, was found to melt at 

 86° C. to a transparent liquid, which solidified again at 

 8i° C. Another specimen, from American cotton, fused 

 at 86° C, and became solid again at 82° C. According to 

 Avequin, cerosine fuses at 82° and solidifies at 80°. Car- 

 nauba wax, according to Lewy, melts at 8 3°. 5. When 

 heated on platinum-foil, cotton-wax gives off an odour 

 resembling that of burning fat, and then burns with a 

 bright flame, without leaving any ash. If heated in a tube 

 it melts, emits a penetrating odour, and then volatilizes 

 completely, yielding an oily sublimate which soon becomes 

 solid and crystalline, and seems to consist of unchanged 

 substance. Singular to say, cotton- wax, when pure, is 

 quite insoluble in caustic alkalies ; and it is therefore diffi- 

 cult to account for its presence among the products ex- 

 tracted from cotton by soda-lye, unless it be assumed that 

 it exists originally, not within the fibre, but on its surface, 

 and is merely fused and mechanically detached by the 

 action of the hot liquid. When treated with boiling dilute 

 caustic soda-lye, it melts without dissolving, and the fil- 

 tered liquid gives only a trifling precipitate with acid; 

 but when carefully heated with hydrate of soda, it yields a 

 compound Avhich is entirely soluble in water; and the 

 solution now gives, with acid, a copious white flocculent 

 precipitate, which consists of a true fatty acid, formed by 

 a process similar to that of ordinary saponification, or 

 more so perhaps to that by which alcohols are converted 

 into the corresponding acids. When cotton- wax is treated 



