The Hottentot Fig as a Possible Commercial Source of Tannin.

Domestic sources of drugs, always potentially iimportaiit, have increased significancoe in time of war when foreign markets are -unavailable or noniexistent. With this thought in mind, a preliminaryexaminationl was made of Mesenmbryanithem?,um edldi L., commonlly known as the Hottentot Fig, as a possible source of tannins. The great astringency of the sap which can be readily demonstrated by the simple expedient of drawing lightly the freshly cut suirface of a leaf across the tonogue, suggests the presence of relatively large amounts of tannini in this plant. The species, a native of the arid plains and sands of Soutth Africa, has spread to mainy parts of the world and thrives in dry, rocky or sandy soils where, due to its prostrate habit of growth, it forms dense succulent mats. Material for the present work was collected on the groutnds of the University of California Medical Center. Freshly collected leaves and stems were dried to eonstanit weight at 1200 C. Then the miiaterial was extracted with twenty volumes of water at 50 to 60° C. for thirty min-utes. Filtration of the resultanlt solution yielded a light amber-colored and slightly opaque liquiid whlielh was testedl with FeCl3, neutral and basic lead acetate. The slightlyacid reaction of the filtrate, the green coloration with FeClb and precipitationi with lead acetate all pointed to the presence of tannins. Further tests made with lead acetate and bromine water showed that the tannini in Mesemnbryanthernunt eduli is of the catechol or phlobotannin type. Although the pyrogallol tannins have found more general industrial applicationis, the catechol tainnins can be used extensively also in many industrial processes, inelucding the tanning of leather. TIme exact nature of the leather produiced can be determinied only by experimentation, however. It seems entirely possible that differenit classes of leather can be produced byusing this tanniin in conjunction with other materials. Quantitative anialysis of oveni-dried Mesemubryanthemum showed 19.4 per cent. tannin in the leaves, and 14.16 per cent. in the stems. Analysis of mixtures of stemis and leaves revealed 17.1 per cenit. taiininis. The material used in these tests was collected durino Juine and Juily, alnd it is not known how these percentages might vary at differenit seasonis. It is apparent that the differeniee in tannin-content between the leaves andl mixtures of the leaves and stems is niot sufficient to warrant the use of leaves exclusively if the plant is to be considered as a possible comimiercial souirce of tannin, since separation of the leaves from the stems is a tedious anid tinmie-consumling task. The analysis indicates that Mesenrabryanthena)nt edulti is a good potential souirce of tannin. It is widely distributed in sandy anid rocky regions of the 384