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HE colloids of honey h a v e received very T little a t t e n t i o n from investigators working in the field of honey c h e m i s t r y , probably because of the relatively small quantities occurring in honey and also because of the heterogeneous nature of the colloidal material itself. 0 b serv a t i o ns which the writers have made, however, indicate that colloids play a very i m p o r t a n t part in influencing many of the properties of honey. Industrial Importance of Investigation of Honey ColloidsThe practicalimportance of a study of the colloids of honey lies in the fact that a large part of the honey produced in certain sections of the United States is too dark and strong-flavored to permit its extensive use for table con-The colloid content of honey varies between about 0.1 per cent for some light honeys, and approximately 1 per cent for dark honeys (buckwheat), as determined by means of ultra-filtration through standardized collodion membranes. Preliminary tests made on honeys of several types indicate that constituents present in colloidal condition influence such properties as color, flavor, clarity, caramelization point, and crystallization to a considerable extent.Cataphoresis measurements showed that the colloidal particles of most honeys are positively charged and that the charge can be reversed by increasing the pH of the solution. A n isoelectric point is reached when the particles show no charge, and at this point maximum flocculation of colloidal material takes place. Determinations of the isoelectric point of several honey samples gave very nearly the same value, namely pH 4.3. Above a pH of 4.3 the colloidal particles are negatively charged ; below 4.3 they are positively charged.Flocculation of honey colloids can be brought about by the addition of appropriate quantities of bentonite, a colloidal clay whose particles are negatively charged. The action is one of mutual flocculation of oppositely charged colloids, and results in a brilliantly clear honey, which is lighter than the original in color. This process promises to be valuable as a means of improving the quality and marketability of low-grade honeys.flavoring compounds, etc. A buckwheat-honey solution, after removal of a considerable proportion of colloids by ultra-filtration and evaporation under diminished pressure to the original honey density, exhibited some interesting properties. The original honey, when tested for its ability to withstand elevated t e m p e r a t u r e s (a standard candy test was used), discolored and caramelized before the maximum temperature used in the test (143" C.) was a t t a i n e d . The same dark honey after removal of colloids was equal in cooking qualities to some of the best light honeys. When the colloidal material that was removed was dried in a vacuum oven a t 70-75" C., it decomposed to such an extent as to resemble a mass of carbon.These results show in a striking way the effect of the sumption. This low-grade honey must be disposed of at a relatively low price, much of it finding its way in...

THEfactors governing crystallization of honey are not thoroughly understood, but it is well known that certain floral types, such as túpelo and sage, remain liquid for long periods of time, whereas alfalfa and some of the clover honeys soon become solid, owing to formation of dextrose crystals.Browne (5) has pointed out that the noncrystallizable túpelo honey is characterized by an abnormally high percentage of levulose.

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