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Vol. 68 g. of tartronic acid and made up to 50 ml. with water.

Considerable interest has developed in pectinic acids (colloidal polygalacturonides, partly esterified with methyl alcohol) that have lower ester contents than those used commercially for high-solids gels. Although investigations concerning the preparation of such pectinic acids have been thorough and methods have been devloped using acid (4,10,15,19,20), alkali (17,18), and enzymes (10, 22), little information is available on the effect of the catalyst on the properties of the products. Hills, White, and Baker (10) have reported that enzymatically deesterified pectins form weaker calcium gels and are more sensitive to precipitation by calcium than are pectinic acids deesterified by acid.Baker and Goodwin (5) and Hills, Mottern, Nutting, and Speiser (9) compared the gel-forming characteristics of several pectinic acids prepared in different ways. Speiser, Hills, and Eddy (25) have found that the acid behavior of pectinic acids prepared with acid is similar to that of pectinic acid prepared with tomato pectinesterase (pectase). These investigations comprise the only recent work in this field.This paper is concerned with the effect of method of deesterification on the viscosity behavior of pectinic acid solutions at different pH values and with degree of dissociation of pectinic acids of varying methoxyl contents.

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sium phthalimide by the conventional procedures.**6 7 Hydrolysis of these compounds by hydrazine hydrate* was more satisfactory than hydrolysis by concentrated hydrochloric acid.The diamines are listed in Table I. They are colorless, viscous liquids, insoluble in water. They are hygroscopic and absorb carbon dioxide from the air. Efforts to prepare the usual solid derivatives yielded oils which would not crystallize. The hydrochlorides were too hygroscopic to be of value as derivatives.