~~ 
ON COLLOID CHEMISTRY AND ITS INDUSTRIAL APPLICATIONS. 47 
second method because the adsorption of the suspended colloid may 
change the sign of the diaphragm. Schwerin claims to apply the 
method in the production of pure colloidal silica,*! in the tanning of 
leather, in the purification of gelatine (glue) dyes, metal sols“ and 
alumina* and in the treatment of serum. 
SUMMARY. 
In this report there have been described applications of electrical 
endosmose or of electrical endosmose and cataphoresis in the pro- 
cesses of dewatering peat and other substances ; treatment of clay ; 
tanning; filtration; medicine; separation of colloidal and non- 
colloidal mixtures; and so forth. No mention has been made of 
certain processes, such as the electrical treatment of emulsions and 
the use of addition agents in electro-plating, which are clearly in- 
stances of applied cataphoresis and are so recognized. 
British Patents. Hlectro-osmotic Processes. 
In the case of Patents dated as of the years 1900 to 1913 inclusive 
the original Specifications have been consulted. The information 
contained in the more recent patents has been obtained from 
Chemical Abstracts and other sources. 
1900. 
12431, July 10. B. Schwerin, Munich. “ Improvements relating 
to the extraction of water or other liquid from mineral, 
vegetable and animal substances.” Evidently first British 
patent. Discusses electrical endosmose, the utilization of the 
“motorial”’ action of the electric current in removing water 
from peat and describes apparatus for so doing. 
1901. 
8086, April 19. B. Schwerin, Munich. “ Improvements relating 
to the extraction of sugar. Sliced beet-roots placed between 
pervious walls and submitted to electro-osmose and elec- 
trolysis. Sugar, soluble albumin and water driven to 
cathode. Places water between solid material and anode; 
the acids in the beets collect by electrolysis in the anode 
liquid and are prevented from inverting sugar. Describes 
apparatus. 
22301, November 5. B. Schwerin, Berlin. Cf. 12431 (1900). 
' Describes apparatus for dewatering peat. 
1908. 
1717, Jan. 23. J. Doull. Use of electric current in drying 
materials. 
14195, June 25. OC. D. Abel for Siemens and Halske A. G., 
Berlin. Elaborate discussion of electrical endosmose and 
4l Brit. Pat. 9237 (1914). 
#2 Brit. Pats, 21448, 21488 (1914). 
43 Brit. Pats. 9565, 9566 (1916). 
44 Brit, Pat, 9261 (1914). 
45 Brit. Pats. 6727, 7212 (1915). 
