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THE CLARIFICATION OR DEFECATION OF THE JUICE.2. Phosphoric acid and soluble phosphates and acid phosphates of theakalies and alkaline earths and of aluminium.3. Salts of aluminium in combination with bodies designed to produce aprecipitate of alumina, and including the aluminates of the alkalies and of thealkaline earths; the precipitation of alumina within a sugar solution whetherfrom an alum or aluminate produces a notable clearing of the solution and thecarrying down of much colloid matter, hut the writer is of the opinion thatthe value of the amount of material required is greater than the benefit to beobtained, in addition to the difficulty of handling the very bulky gelatinousprecipitate formed.4. Salts of the heavy metals, especially of lead, zinc and tin. All ofthese produce copious precipitates, but their poisonous nature is an insuperableobstacle to their use.5. Baryta and its salts, and in combination with other agents. Baryta iscertainly a powerful clarifying agent, but its poisonous nature, as well as theexpense involved, prevents its use.6. Agents designed to the removal of potash, including the use offluosilicic acid and its salts, and filtration through layers of calcium aluminiumsilicates.7. Unclassified agents, including ozone, chlorine, hypochlorous acid,hydrofluoric acid, permanganate of potash, chromic acid, tannic acid oftensuggested to be used in combination with aluminum salts, oxalic acid in conibinationwith lime, clay, brick dust, oils, kieselguhr, albumen.8. Electrical processes.Of later processes that have been proposed may be cited those of Ranson 7 ,which include the use of zinc, tin, hydrosulphurous acid, hydrogen peroxide,and aims at a decoloration of the juice and direct manufacture of white sugarby alternate oxidations and reductions. Gans 8 proposes the use of artificialzeolites or calcium aluminium silicates as a filtering material, whereby thepotash of the juices is replaced by lime; this material was placed on themarket under the name of ' Permutit,' but Claassen 9 , who examined its action,found that, although the potash could be thus removed, the viscosity of theresulting material due to the substituted lime salts was much increased, andhe was unable to recommend its use. Hlavati 10 proposes the removal ofpotash by means of fluosilicic acid, and Besson 11 employs powdered aluminiumalloys in an alkaline juice to obtain a precipitation of alumina and decolorationthrough the agency of the hydrogen evolved. "When this plan is used in thejuice in the evaporation, a diminution of the deposit of scale and an increasedtransmission of heat is claimed.A detailed list of the various proposalsLippmann 12 .has been given by von251