[Block-impregnation technic for the histological demonstration of chloride ions]

Authors worked out a new method for the histological demonstration of chloride ions by modifying old techniques. Unfixed, fresh tissue pieces are treated with silver nitrat, then embedded in paraffin. Chloride ions present in the tissue react with silvernitrate, thus forming silver chloride. Silver salts of other anions present in the tissue can be eliminated with weak solution of nitric acid, thus silver precipitate formed by reduction of silver chloride indicate only the localization of chloride ions. This method seems to be suitable for the demonstration of chlorid ions in the parietal cells of the stomach and for the lokalization of reabsorbed chloride ions in the renal tubules.