56 REPORTS ON THE STATE OF SCIENCE.—1918. 
The colloidal state of cellulose is modified in the direction of 
distension by treatment with strong alkalies, caustic soda, caustic 
potash tetramethyl-ammonium-hydroxide and by several other sub- 
stances. A still greater degree of swelling is produced when cotton is 
overworked in the hollander used in the paper-making industry.” 76 
The maximum degree of dispersion is attained when the cotton is 
treated with cellulose solvents. 
It has been observed that freshly precipitated cellulose is soluble 
in caustic soda but that this solubility disappears when the cellulose 
is dried. A similar change is produced when precipitated starch is 
dried. These changes are the common result of gel-dehydration. 
Iodine forms a useful reagent in conjunction with hydrating 
agents such as potassium codide, zine chloride and sulphuric acid, 
for indicating the different colloidal states of cellulose. The strength 
of hydrating agent required to give the blue colour indicates the 
degree of dispersion of the cellulose. It is interesting to note that 
starch celluloses can be prepared which give the blue colour with 
iodine. under the same conditions as cellulose.22. This does not neces- 
sarily imply that there is any chemical relationship between starch 
and cellulose since the blue colour has been shown to be due to 
colloidal iodine and numerous substances have been found which 
give the reaction. 
(B). Cotton : 
Books of Reference. 
1 Cross & Bevan, Cellulose and Researches. 
? Schwalbe, Die Cellulose. 
3 Worden, Witrocellulose Industry. 
£0. N. Witt, Chem. Tech. der Gespinnst-fasern Braunschweig, (1888). 
5 Monie, The Cotton Fibre, London, (1890). 
® Bowman, The Structure of the Cotton Fibre. 
7H. Kuhn, Die Baumwolle. 
8 Flatters, Zhe Cotton Plant, (1906). 
9 W.L. Balls, Zhe Development and Properties of Raw Cotton, (1915). 
References. 
0 Tollens, Handbuch der Kohlehydrate I1., 252 (1895). 
1 Vignon, Bull. Soc. Chem., 21, 599, (1899). 
12 Bernadou, (Compare (2), p. 349). 
13 Cross & Bevan, Zrans. Chem. Soc., "79, 366, (1901). 
4 A.G. Green, Journ. Suc. Dyers § Cols. 20, 117, (1904). 
18 Cross & Bevan, Ibid. 32, 135, (1916). 
16 A. EH. Sunderland, Zbid. 32, 230, (1916). 
7 Crum, Trans. Chem. Soc., 1, 409. 
8 Muller Jacobs, Jowrn. Soc. Dyers 5 Cols., 11, 95, (1885). 
19 H. De Mosenthal, Journ. Soc. Chem. Ind., 23, 292, (1904) ; 26, 443, (1907). 
*0 Haller, Zeit. fiir Farben wu. Textil Chem., 8, 125, (1907). 
"1 Herzog, Koll Zeit., 5, 246, (1909). 
#2 W. Harrison, Journ. Soc. Dyers § Cols. 31, 198, (1915). 
3, W. Harrison, Zrans. Nat. Assoc. Cotton Manfrs., 101, 201, (1916). 
*4 Haller (Structure of Cotton), Koll. Zeit., 20, 127, (1917). 
*° Cross, Papier Zeitung, 33, 3246, (1908). 
*6 Briggs, Papier Fabrikant, 5, 2644, (1907); 46, (1910). 
*7 Fenton (Action of hydrochloric acid), Zrans. Chem. Soc., 93, 554, (1898) ; 75, 
427, (1899) ; 79, 361, 807, (1901) ; 99, 1193, (1911). 
*6 Erdmann & Schaeffer, Ber., 43, 2398, (1910). (Dry distillation of cellulose). 
*® Pictet and Sarasin, Comp. Rend., 166, 28, (1918). (Dry distillation of cellulose 
and starch). 
30 Sarasin, Arch. Sci. phys. Nat. (1918) pp. 5-32. 
31 Fort, Journ. Soc. Duers § Cols. 34, 9, (1918). 
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