Original method of showing some constitutive elements of the capillary wall.

The ascorbic acid and the 1-epi-3', 4', 5', 5, 7-pentahydroxy-flavan-3-ol have been located in the blood capillary wall by an histochemical method for electron microscopy. The method consists in an intra-arterial administration of vegetal oxydases specific of the compound to put in evidence. Those oxydases fix themselves on their effectors, and the addition of osmium and lead salts gives co-precipitates opaque to electrons.