In order to separate the lactic acid from the colouring matter and other bodies (dextrin and soluble starch) present, 100 c.c. of the concentrated liquid was decolorised with 10 grm. of animal charcoal, the mixture filtered and the charcoal well washed, the filtrate evaporated to dryness, and 15 drops of N/10 H_{2}SO_{4} added to decompose any salts of lactic acid present; this was now extracted with ether, the ethereal extract of lactic acid placed in a distilling-flask, the ether distilled off, and the residue boiled with distilled water and pure calcium carbonate. The small amount of calcium sulphate present was removed by boiling the filtrate from the CaCO_{3} with barium carbonate, and filtering. The filtered liquid now consisted of a solution of calcium lactate; it was evaporated to dryness in a platinum dish, and the residue dried at 110° C.; it was then washed first with ether, then absolute alcohol.[166] [166] Julius Wladika. _Vide_ Der Gerber, xvi. 28. Zur Kenntniss der Organ. Säuren in Fichtenbrühen. The insoluble residue was dried at 110° C. till the weight was constant. The total weight of calcium salts obtained was 0·7661 grm. (from 4/5 litre of drench), of which 0·5493 grm. yielded on ignition 0·1398 grm. CaO = 25·45 per cent. Theory requires for calcium lactate (C_{3}H_{5}O_{3})_{2}Ca = 25·69 per cent. CaO. 0·7661 grm. calcium lactate in the quantity used = 0·9576 grm. per litre = 0·7907 grm. lactic acid per litre. The difference between this and the preceding amount of lactic acid found by titration, viz. 0·0426 grm., is probably accounted for by the presence of a small quantity of salts of lactic acid in the drench. The second part of the subject which we proposed to consider was “In what way does the ferment act on the bran and on the skins?” The average composition of bran is shown in the following table:-- Per Cent. Water. 14 Fibrin, etc. 15 Starch 44 Fat 4 Lignose and cellulose 17 Ash 6