ON COLLOID CHEMISTRY AND ITS INDUSTRIAL APPLICATIONS, D1 
1914. 
6993, Mar. 19. Elektro-osmose Akt. Gesellschaft (Schwerin). 
Facilitates dewatering of peat by previously subdividing 
material in a ball mill and adding electrolyte such as NaOH 
‘| to increase the rate of cataphoresis and endosmose. 
_ 6995, Mar. 19. Elektro-osmose Akt. Gesellschaft (Schwerin). 
Cf. 6993 (1914). Adds adsorbed colloid before grinding 
peat. Colloidal silicic acid or humic acids are suitable. By 
adding sodium silicate obtains both a suitable electrolyte 
(NaOH) and colloidal silica. Adsorbed colloid peptizes the 
solid and being strongly electro-negative in dilute NaOH 
hastens the migration to the anode. 
9237, Apr. 14. (Gesellschaft fiir Elektro-osmose (Schwerin). 
Electro-osmotic preparation and purification of colloidal 
silicic acid. Places 5 to 10 per cent. sodium silicate solution 
between two porous diaphragms—one around cathode and 
the other around anode. By using a newtral diaphragm 
(composed of carborundum plus alundum) about the cathode, 
the alkali is electrolyzed out of the sodium silicate, and no 
silica is carried into the cathode compartment, since no 
electrical endosmose takes place through the cathode dia- 
phragm. With parchment above anode, no colloidal silica can 
get into anode compartment but soluble acids can do so. 
Obtained colloidal solution of silica in the middle compart- 
ment. Platinum or lead-antimony fanodes ; brass gauze 
cathodes. Typical ‘electro-osmotic” multiple diaphragm 
process. Cf. German Pat. 283,886, Apr. 15, 1913. 
9261, Apr. 14. Gesellschaft fiir Hlektro-osmose (Schwerin). 
Making stable metal sols by using colloidal silicic acid as 
protecting agent, reducing metal salt with hydrazine hydrate 
and purifying subsequently by process such as specified in 
9237. 
118238, May 13. Gesellschaft fiir Elektro-osmose (Schwerin). 
Separating colloids, etc. by electrical endosmose and cata- 
phoresis. 
19849, Sept. 16. Gesellschaft fiir Elektro-osmose (Schwerin). 
Tanning and dyeing by electro-osmose. Places leather or 
adsorbing substance together with tannin solution in com- 
partment between two or more diaphragms, impervious to 
tannin but pervious to dissolved electrolytes. Claims simul- 
taneous purification of tannin solution by electrolysis and 
impregnation of leather. 
21189, Oct. 19. Gesellschaft ftir Elektro-osmose (Schiverin). 
Changes interface potential of diaphragms by addition agents. 
Thus Cr203, makes a leather diaphragm more positive (leather 
adsorbs Cr.03 which is distinctly electro-positive). Methylene 
blue (basic dye) makes viscose positive: (viscose adsorbs the 
dye cation). Adsorbed acid dyes make diaphragms electro- 
negative. Interesting patent based on selective ion adsorption 
or on the adsorption of charged colloids. 
21190, Oct. 19. Gesellschaft fiir Elektro-osmose * (Schwerin). 
Modifies 19849 to allow preliminary purification of tan liquor. 
