ON COLLOID CHEMISTRY AND ITS INDUSTRIAL APPLICATIONS. 65 
Transformation of cyclobutane derivatives ‘Journ. Soc. Chem. Ind.’ 1916,35, 381 
into erythrene. 
Synthesis of the symmetrical bromide of oe x + a 368 
erythrene-caoutchouc, of caoutchouc 
itself and of caouprene. 
Preparation of esters of unsaturated alcohols 5 PP P = 382 
from aldols. 
Polymerisation of ethylenic compounds and oe 33 5 369 
mechanism of transformation of vinyl 
bromide into bromide of erythrene- 
caoutchouc. e 
Analysis, purification, and reactions of ie sf re 
isoprene. 
Polymerisation of isoprene. divinyl and ‘Journ. Chem. Soc.’ 1917, 112, i. 399 
dimethylerythrene to caoutchoue or 
its homologues. 
Preparation of substances equivalent to 5 ‘¢ ” 3 i. 403 
ebonite, celluloid or gutta percha. 
Synthesis of vulcanised caoutchouc. 
_ Synthesis of the symmetrical chloride se si oe Pe i, 404 
and of the higher chloride of erythrene 
caoutchouc. New chlorides of natural 
isoprene and erythrene caoutchoucs. 
(‘J. Russ. Phys. Chem. Soc.’ 1916, 
46, 1132-1151.) 
B. D. W. Lurr (‘ Journ. Soc. Chem. Ind.’ 1916, 35, 983). ‘Some Aspects of the 
Synthesis of Caoutchouce.’ 
Konpakow (‘ Caoutchouc et Gutta Percha,’ 1917, July15). Deals historically with 
his own researches. 
Note.—‘ Rubber,’ by Dr. H. P. Strvens, forms one of the sections in the ‘ Annual 
Reports on Industrial Chemistry,’ vol. i., issued by the Society of Chemical 
Industry. 
——— 
COLLOID CHEMISTRY OF STARCH, GUMS, HEMICELLULOSES, 
ALBUMIN, CASEIN, GLUTEN, AND GELATINHE. 
By H. B. Srocxs, F.I.C. 
Starch. 
, 
The application of starch in the sizing and finishing industries, for which 
it is used in very large quantities, depends entirely upon its colloidal 
properties. That is, on heating with water, it forms a plastic mass, or 
adhesive sol, according to the concentration and the temperature. It can 
therefore be readily applied to textile fibres or fabrics. In the sizing 
_ industry it is applied to the yarn—the warp—to strengthen it, render it 
: smoother (i.e., lay the individual fibres), and thus facilitates weaving, while 
in heavy sizing it acts as a binder to hold the weighting material, usually 
_ china clay, which is employed. For these purposes, although very useful, 
_ it is not altogether perfect, since, on drying, it does not form a continuous 
~ 
« 
film. In calico-printing it is one of the mediums employed for carrying 
or thickening the colours, thus preventing them spreading into the 
Surrounding tissues. For these purposes potato starch or farina, wheat- 
_ starch and wheat-flour, sago, tapioca, maize, cassava, and rice-starch are 
ot 
t is well known that the granules of the various starches vary in 
appearance under the microscope, they also vary somewhat in their 
properties ; for instance, sago, tapioca, and cassava starches yield more 
1917. F 
i 
q 
