ON COLLOID CHEMISTRY AND ITS INDUSTRIAL APPLICATIONS. 41 
pervious metallic bottoms serving as cathodes and the anodes pressed 
down from above upon the peat. The Hiéichst Color Works 
experimented with Schwerin’s process on a semi-commercial scale 
and took out several additional patents’ on improvements of 
apparatus and procedure. Other patents were taken out in Great 
Britain by Siemens and Halske,® Doull,’ Kittler,s Verey and Downes® 
and Simm," although the last named inventor really used the current 
for heating purposes only." 
Schwerin,” addressing the Bunsen Society at the Fifth Inter- 
national Congress at Berlin in 1903, discussed some of the pre- 
liminary experiments made with his process and attracted at the 
time a good deal of attention. Starting with a peat mud containing 
originally nearly 90 per cent. moisture, it was claimed that a volume 
of water equal to three-fourths the volume of the mud could be 
removed and that this could be done with an expenditure of only 
one-fifth part of the energy available in the recovered peat. The 
most suitable potential gradient through the peat was stated to be 
4 or 5 volts per centimetre and 13 to 15 kilowatt-hours were required 
in removing one cubic metre of water. Unfortunately, the peat 
obtained at the end of the treatment contained as high as 65 per 
cent. of moisture, although the material itself was easily amenable 
to moulding into bricks ur other shapes. It was therefore necessary 
to subject the moulded peat to prolonged and tedious drying in the 
air, in order to reduce the water content to the permissible maximum 
of 20 per cent. 
Promising as Schwerin made his process appear, it proved a 
failure when tried out on a commercial scale apparently because air- 
drying the material with 65 per cent. moisture proved to be far more 
tedious and costly than experience with 50 per cent. material had 
led those interested to expect.’ Nevertheless, it is possible that the 
method may some day prove feasible if the electro-osmotic treatment 
can be improved to yield a product with less than 50 per cent. of 
moisture ; such an improvement might be brought about, as Foerster 
suggests, by previously disintegrating™ the jelly-like aggregates in 
the original peat and thus permitting closer packing of the peat 
solids. A very large proportion, however, of the water in peat is 
adsorbed, and the difficulty as I see it lies in the removal of this 
adsorbed moisture; only water held mechanically can be removed 
by electro-kinetic processes.” 
In recent years Schwerin has endeavoured to improve things by 
applying to his purposes some of the newer knowledge gained from 
5 Brit. Pats., 3795, 24670 (1904) Farbwerke, vorm. Meister Lucius u. Briining. 
6 Brit. Pat., 14195 (1903). 
7 Brit. Pat., 1717 (1903). 
8 Brit. Pat., 126 (1904). 
® Brit. Pat., 2226 (1907). 
Brit. Pat., 4792 (1905). 
1 Cf. Davis: Bull. U.S. Bur. of Mines, 16, 122 (1912). ‘ j 
12 Ber. V. int. Kong. angew. Chem., 4, 653 (1903) ; Zeit. Hlektrochemie, 9, 739 
(1903). 
13 O f. Foerster : Hlektrochemie, 118 (1915). 
14 Of, Brit. Pats, 6993, 6995 (1914). as 
15 The same difficulty arises in the removal by cataphoresis of iron oxide from 
clay. Cf. the “osmose” process of clay purification, 
