ON COLLOID CHEMISTRY AND ITS INDUSTRIAL APPLICATIONS. 45 
Preservation of Timber. Electro-osmotic _Impregnation. 
At various times it has been proposed to dry timber by electro- 
osmotically removing the sap. While electrical endosmose can 
scarcely ‘prove suitable for this process alone, it might be very 
effective in replacing the sap juices with liquid disinfectants. 
Alcock and Company, Proprietary, Ltd.,* of Melbourne, propose to 
impregnate timbers electrically, by placing them on end in a shallow 
cathode vessel containing a conducting liquid and driving into the 
upper ends hollow metal anodes filled with the liquid preserving 
medium with which the wood is to be impregnated. On passing a 
current, electrical endosmose to the cathode takes place, sap is forced 
out of the timber and into the lower receptacle and its place is taken 
by the liquid preservative forced in at the top. If the consumption 
of electric power is not too great, the method ought to prove a 
success. In this connection it is interesting to find a note* to the 
effect that the injury to trees caused by stray currents may be due to 
electrical endosmose. This is quite possibly true in case the electric 
current is a direct one. . 
Manufacture of Bricks. Lubricating Metal Surfaces in Contact 
with Clay. 
A very effective and apparently mysterious process which is 
unquestionably an application of electrical endosmose was announced 
by Dawkins*® in 1913 at the Chicago Convention of the National 
Brick Manufactures Association. Wet clay has a distinct tendency 
to adhere to smooth metal surfaces. To prevent this a lubricant is 
used, the lubricants iucluding oils, emulsions and water itself. 
Water is particularly useful because a layer of it on the metal 
prevents the clay from sticking, softens the surface of the clay as it is 
being cut or moulded and gives the brick a smooth finish. It was 
found that if metal in contact with the clay is made cathode and a 
current is passed, the clay no longer tends to adhere and all the 
effects of lubrication are duplicated. In making wire cut bricks 
electrical “lubrication ” is said to reduce the power consumption by 
25 to 30 per cent. 
It has been suggested that the current forms a layer of hydrogen 
over the electrode and that this causes the appareut lubrication. 
What really happens is this: when the current flows water is carried 
through the clay to the cathode (the metal) and forms a layer 
between it and the clay ; it is this layer of water which prevents the 
clay from sticking and acis as a lubricant. 
ELECTRO-THERAPEUTICS. ELECTRO-OSMOTIC INFILTRATION OF 
DRUGS.** 
Shortly after the early experiments, especially those of Wiede- 
mann, had demonstrated the ease with which electrical endosmoge 
31a Brit. Pat. 25175 (1910). 
32 Schneckenberg : Hlektrochem. Zeit., 19, 151 ; Chem. Abstr. 
33 Clayworker 57, 426 (1912) Cf. Brit. Clayworker : 99, 91, 92 (1913). 
34 Morton: Cataphoresis (1898) ; Herdman: Bigelow’s Internot. Sys. of Thera- 
peutics, 30, (1894) ; Peterson : Zbid. C 1 (1894); Jones : Med, Electricity (4th Ed.) 
230 (1904) ; Traube and Berczeller : Internat. Zeit. Biol. 2, 107 (1915). 
