436 SECTIONAL TRANSACTIONS.—B. 
3. Salis of polybasic acids of anhydrides Al,SiO,, AlpSivO,, Al,SisO, . . . 
Chlorites A1,Si0;_»(EO) op AlpSizO;_(HO)on 
Mostly hydrated Mg and Fe compounds. 
Melilites, polygorsaites, &c., are products of addition pA gB 
A—silicate 
B—contains Al 
and do not belong to the alumosilicates. 
Tuesday, September 18. 
15. Miss Euizasera S. Semmens.—The Biochemical Effect of 
Polarised Light. 
That plane polarised light has a distinct accelerating effect on the breaking 
up of starch grains in the presence of diastase can be shown under the micro- 
scope. At laboratory temperatures below 20° and with small concentration of 
diastase, starch grains exposed to light polarised by reflection or by a Nicol 
prism erode quickly and give crystals of sugar, controls in ordinary light or 
in the dark remaining almost intact. If the diastase is concentrated, the starch 
grains exposed to ordinary light also undergo hydrolysis. Above 25° erosion 
takes place in the controls kept in the dark. 
16. Dr. R. G. Farguer.—Cotton Waz. 
The term ‘ cotton wax’ has been applied by different writers to the extracts 
obtained from cotton by means of organic solvents, and even to the material 
removed by boiling the cotton with dilute sodium hydroxide. Generally, it 
includes fat, wax, and the more readily soluble portion of the resin present 
in the cotton, the proportion of fat being relatively small. This material 
interests the spinner and manufacturer, as it probably lubricates the hairs 
during spinning and the preceding processes, and to some extent cements them 
in the spun yarn; whilst the bleacher and finisher consider that it must be 
efficiently removed if the maximum effect of certain finishing processes is to be 
attained. 
Comparison of the extracts obtained with a number of organic solvents 
indicated that carbon tetrachloride removed the fat and wax and left the 
major portion of the resin undissolved; whilst chloroform, using a ‘ hot’ 
soxhlet, dissolved fat wax and resin. The characteristics of the crude wax 
obtained from three cottons—American Upland, an almost pure strain American 
cotton grown in the Mississippi Delta, and Egyptian Sakellaridis—are given. 
Special analytical methods have been devised for dealing with very small 
quantities of material. 
The character of cotton wax indicates that emulsification must play a con- 
siderable part in its removal during scouring; this has been shown to be the 
case by large-scale trials. : 
17. Dr. D. A. Cuispens.—The Absorption of Methylene Blue by 
Cotton. 
A quantitative investigation of the conditions which determine the absorp- 
tion of methylene blue by bleached cotton from neutral solutions of methylene 
blue hydrochloride. The object of the work has been to provide a method for 
determining the efficiency of cotton-bleaching processes with respect to their 
production of pure cotton cellulose. The bleaching of raw cotton involves two 
distinct series of operations : (a) ‘ scouring,’ which consists of a treatment, or 
series of treatments, with hot dilute alkalis, and which effects the removal of 
the greater part of the non-cellulose impurities, and (6) the bleaching process 
proper, in which the scoured material is treated with dilute oxidising solutions. 
Measurements of the absorption of methylene blue at various stages of a bleaching 
process show :— 
1. The absorption by raw cotton is high, and is a property not of the cellu- 
lose itself, but of certain acidic non-cellulose impurities. 
2. The absorption diminishes progressively; it indicates and measures the 
ll a elt 
