solution with the potent substance and also tended to destroy the ensymes, including trypain, erepsir, and the proteases.
When cooled the lipoids were removed and the mixture was filtered. 100 cc of 25% sodium benzoate solution and 25 cc of concentrated hydrochloric acid were separately added to each litre of the aqueous extractive filtrate, and these formed a precipitate of benzoic acid in a finally divided state, which carried with it the potent substance as by adsorption. The benzoic acid precipitate with the adhering potent substance was then separated from the filtrate by further filtering or by centrifuging and when separated it was washed with a saturated aqueous solution of benzoic sold to free it from any of the filtrate from which it had been precipitated. The washed precipitate was then dried and the resulting product was a powder containing the potent substance or extract practically free from injurious substances. Although kept for a considerable time the potency of the substance in this form did not appreciably deteriorate under proper conditions of sterility and temperature.
200 cc of 80% alcohol were added to the washed precipitate to dissolve the benzoic acid and potent substances and this solution was stirred or agitated and then allowed to stand so that any inert material could settle, after which it was filitered. After filtration the major portion of the alcohol was boiled off from the filtrate which was then shaken with ether and water and allowed to stand, when two layers were manifested. The lower aqueous layer contained the potent substance in concentrated and purified form and the upper layer contained the benzoic acid. The lower aqueous layer was separated from the mixture and washed with