1868. ] Chemistry. 387 
The extraction of oils by means of bisulphide of carbon is now 
carried on at Moabit, near Berlin, upon a very large scale. In the 
manufactory of M. Heyl, 2,570 kilos. of oil, of sufficiently good 
quality to be employed in lubricating machinery, are manufactured 
daily. Colza and linseed are the materials chiefly operated upon ; 
the residues serve very well to feed cattle with. The seeds are first 
crushed and dried by heating. For the daily fabrication of 2,570 
kilos. of oil only six men are required. Analysis has shown the 
residues to contain only 2 per cent. of oil and 7 per cent. of water, 
while the residues of the ordinary pressure process contain 9 per 
cent. of oil and 15 per cent. of water. In the extraction of the oil, 
7,000 kilos. of bisulphide of carbon are used daily, and the amount 
lost is 28 kilos. 
M. Rakowitsch proposes a method of examining flour by means 
of chloroform. The following are the results which he says may 
be gathered from an experiment capable of being made in a few 
minutes:—The amounts of bran, the moisture between 10 and 25 
per cent., the damaged flour, the mineral matters, the ergot of rye, 
and other impurities. The whole of these are determined by the 
relative specific gravities of the different substances in chloroform. 
The flour is simply placed in a tube and mixed with chloroform ; the 
chloroform is enabled to hold in very thorough suspension the pure 
flour, while the other materials are not thus suspended. By adding 
spirits of wine of 95°, the flour is precipitated to the bottom of the 
tube. The more humid the flour, the more spirits of wine must be 
added, and thus the amount of humidity in the flour is arrived at. 
The employment of charcoal filters has long been advocated, on 
account of the known property of this substance to absorb and 
oxidize organic matter. Mr. W. Skey, of New Zealand, has now 
shown that charcoal will remove arsenic from water. Ifa few drops 
ef a solution of a salt of arsenic, or arsenious acid, be put into a few 
eunces of dilute sulphuric acid, and the mixed solution agitated at 
intervals with recently ignited charcoal for an hour or two, the clear 
liquid obtained by filtration does not manifest any reaction of arseni¢ 
when tested by Marsh’s process. Tungstic acid also is removed from 
acid solutions by charcoal applied in like manner, and is given up 
to a solution of caustic alkali. 
PROCEEDINGS OF THE CHEMICAL SocrETY. 
The subject of water analysis still occupies the attention of this 
society to an extent entirely out of proportion to the merits of the 
inquiry. At the meeting on March 5th, Messrs. Wanklyn and 
Chapman read a long paper “On the Action of Oxidizing Agents on 
