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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    Table VI—Composition of the Potassium Salts Formed by Neu- tralizing that Part of the Edestin Preparation that was Insoluble in Water. Gram. In per cent, of the Inorganic matters. Organic matters O.0574 5.8 Insoluble mineral matter 0.0067 Potassium carbonate O.OI2I 10.5 Potassium sulphate O.OII7 IO.I Potassium chloride 0.0710 61.5 Sodium chloride. O.OO85 7-4 Undetermined and loss.. O.OO55 4-7 O.I729 100.0 In this experiment, 75 per cent, of the potassium added was recovered, of which 76 per cent, is chloride and 11 per cent, sulphate. In the similar experiment, to be described on page 411, 85 per cent, of the potassium added was recovered, of which 47.6 per cent, was chloride and 52.4 per cent, sulphate. Since the present experiment yielded so small a proportion of sulphate, it is evident that the insolubility of edestin in water is not simply due to combined sulphuric acid, but, as we shall later show, is chiefly due to the greater proportion of acid combined with the soluble part. To make a preparation which, when neutralized, should yield only chloride, 3,000 grams of hemp-seed meal were extracted with 9 liters of brine heated to 6o° and containing 3 per cent, of almost chemically pure sodium chloride. The filtered extract was cooled to 8° and allowed to stand over night, until the large crop of crystals had been deposited. These crystals were then collected on a filter, washed once with water, redissolved in one liter of sodium chloride brine, the solution filtered perfectly clear, heated to 550, diluted with three volumes of water at the same temperature, and rapidly cooled to o°. The crystalline deposit which separated was suspended in water, brought on a filter, and this process repeated until all the edestin soluble in water was washed out. The three por- tions of washings first obtained were almost protein-free, the fourth contained nearly one-half of the original preparation, the fifth much less, and the sixth very little. fo the fourth portion enough pure sodium chloride was added to form a 10 per cent, solution. This caused at first an abund-