PYROXYLIN 637 



freed from adhering impurities and deprived of fatty 

 matter. 



Habitat — Tropical Asia and Africa ; cultivated in sub- 

 tropical and tropical countries, mostly in the Southern 

 United States. 



Description. — White, soft, fine filaments, appearing under 

 the microscope as hollow, flattened and twisted bands, 

 spirally striate and slightly thickened at the edges ; inodor- 

 ous and tasteless ; insoluble in ordinary solvents, but 

 soluble in copper ammonium sulphate solution. 



Uses. — Absorbent cotton is used as a cheap, convenient 

 and cleanly substitute for ordinary sponges ; to make poult- 

 ices by soaking it in antiseptic solutions (as creolin 1-2 per 

 cent.) and placing it between layers of gauze ; and for surgi- 

 cal dressings. 



Oakum, consisting of the fibres of old rope, is often 

 employed as a cheap absorbent material, saturated with tar, 

 in packing horses feet. 



Tow, — the coarser unbleached fibres of flax ; and lint, — 

 the scrapings of soft, loosely woven linen, — are also utilized 

 as absorbent substances for surgical purposes. 



Pyroxylinum. Pyroxylin. (U. S. & B. P.) 



Synonym. — Gun cotton, soluble gun cotton, colloxylin. 



Derivation. — Made by maceration of purified cotton, 

 100 ; in a mixture of nitric acid, 1400 ; and sulphuric acid, 

 2200 ; at a temperature of 32° 0. (90° P.), until a sample is 

 soluble in a mixture of 1 volume of alcohol and 3 volumes of 

 ether; washing with cold and boiling water, draining, and 

 drying in small pellets. 



PREPARATIONS. 



Collodium. Collodion. (U. S. & B. P.) 

 Pyroxylin, 40; ether, 750; alcohol, 350. Made by solution, agita- 

 tion, and decantation of clear portion. 



Collodium Cantharidatum. Cantharidal Collodion. (U. S. P.) 

 Synonym. — Blistering collodion. 

 Made by percolation of cantharides, 60 ; with chloroform, distilla^ 



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