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A. Seaweed.—By means of a three-compartment cell with ceramic diaphragms, suspensions of dried ground Laminaria cloustoni stipe were electrodialysed to remove inorganic material. The total-ash content of the seaweed was reduced from 33.4 to 7.4% in 30 minutes, representing a removal of 78% of the ash. Tests were also made on dried, ground frond, and a much smaller removal was effected. The total-ash content was reduced from 28 to 22.8% in 30 minutes, representing a removal of about 18% of the ash. Duplicate tests were made to determine the amount of alkali and chlorine recovered and the energy required. The following figures were obtained (per Ib. of dry seaweed): alkali recovered, 0.053 Ib.; chlorine recovered (estimated), 0.056 Ib.; energy required, 3.03 kw. B. Fish albumen.—A three-compartment cell, with diaphragms of cellulosic material, was used for tests to reduce the ash content of fish albumen. It was found possible to reduce the ash content from 7.7 to 4.0% in 90 minutes, representing a removal of 52.3% of the inorganic material. The fact that not all the inorganic material is removed in either A or B is tentatively attributed to the presence of a certain proportion of it in an insoluble form such as calcium alginate in seaweed and calcium citrate in fish albumen. Electrodialysis of calcium alginate and calcium citrate gave results which supported this view.

Variables affecting the electrodeposition of basic magnesium carbonate and calcium carbonate from suspension in organic liquids have been investigated. Temperature has little effect. Deposition increases linearly, in most cases, with voltage, time, concentration and electrode surface. An unusual effect has been noted with high concentrations of materials containing a hydroxyl group, the amount of deposit increasing very rapidly with increasing concentration. With different organic liquids as suspending media, the amount of deposit increases with increasing dielectric constant in the series ethyl acetate, n-amyl alcohol, n-butyl alcohol, n-propyl alcohol, ethanol and methanol. With acetone and nitrobenzene little or no deposition is obtained, whereas cyclohexanone gives a result in agreement with the first series where magnesium carbonate is deposited, but gives no appreciable deposit with calcium carbonate. In certain cases a break occurs in the relationships when the deposit is heavy, possibly because the weight of the deposit causes a partial breaking-off. The mechanical strength of the deposit appears to depend upon the conditions of deposition. It has also been shown that the presence of small amounts of water or of acid has no apparent effect, but larger amounts cause, in the first case, an increasingly wet deposit and in the second, complete inhibition. The purity of the suspending medium can affect the action greatly. Heavy currents obtained during tests on calcium carbonate suspended in methanol are thought to be due to a reaction between these substances.