The basic character of the protein molecule and the reactions of edestin with definite quantities of acids and alkalies.

  • Osborne, Thomas B. (Thomas Burr), 1859-1929.
Date:
[1900]
Catalogue details

Licence: In copyright

Credit: The basic character of the protein molecule and the reactions of edestin with definite quantities of acids and alkalies. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    HYDROCHLORIC ACID IN THE ANIMAL ORGANISM. 44 I potassium or sodium edestin are soluble in pure water, but insoluble in the presence of a small proportion of a neutral salt. In the presence of a larger proportion of the neutral salt they are soluble, and in such solutions they show the properties of globulin. 20. The fact that edestin, as well as its salts with strong- acids, is soluble in perfectly neutral solutions of sodium chloride shows that the solubility of a globulin does not depend on the presence of alkali, as Starke has recently asserted. A TYPE OF REACTION BY WHICH SODIUM CAR- BONATE AND HYDROCHLORIC ACID MAY BE FORMED IN THE ANIMAL ORGANISM. By Thomas B. Osborne. In the preceding paper I have called attention to the basic properties of protein substances and have shown that prepara- tions of the crystalline globulin edestin, as usually obtained from the hemp-seed, are mixtures of salts, chiefly chlorides and sulphates. The nature of this combined acid depends upon the salts present in the solution at the time of precipitation, the acid of the seed sufficing to enable some of each of the acids of these salts to combine with the protein. These facts led me to examine the precipitate produced by carbonic acid, in a dilute sodium chloride solution of edestin, as it seemed possible that this might consist chiefly of chloride. A quantity of a relatively pure preparation of edestin, which had been several times recrystallized from a warm dilute sodium chloride solution by cooling, was suspended in water and made exactly neutral to phenolphthalein by decinormal potassium hydrate solution. The edestin thus neutralized was washed with water and dissolved in sodium chloride brine. The solu- tion was diluted with water until it became slightly turbid and carbonic acid gas was passed through it until the edestin appeared to be completely precipitated. This was filtered out, washed thoroughly with i per cent, sodium chloride solution and then with 50 per cent, alcohol, until no chlorine could be detected in the washings, dehydrated with absolute alcohol and dried over sulphuric acid. The substance thus prepared, while