A study of the proteids of the corn or maize kernel.

  • Chittenden, R. H. (Russell Henry), 1856-1943.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: A study of the proteids of the corn or maize kernel. 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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    collected on a filter, washed with water, alcohol and ether, and when air-dried was found to weigh io.i grams, thus indicating about 0.2 per cent, of globulin in the air-dry kernel, on the assumption that the extraction and separation were complete. The filtrate from this last separation of the globulin was almost entirely free from proteid matter, giving only a very slight reaction with Millon’s reagent, no further separation of any matter by continued dialysis, neither any precipitate on addition of acetic acid or acetic acid and solution of salt, and only the faintest turbidity on boiling. A portion of the globulin dissolved in io-per cent, solution of salt yielded by heat-coagulation much the same results as the previous salt solution of the proteid, viz. turbidity at 58°, forma- tion of flocks at 67°. In the filtrate from this coagulum a second turbidity appeared at 770, followed by flocks at 87°. Further, in this filtrate another coagulum appeared on boiling the solution, so that while the individual temperatures of coagulation were some- what different from the preceding, they point to essentially the same general conclusion. A portion of the globulin was dried at 1 io° C. until of constant weight, and then analysed with the following results: Analysis' of Corn Globulin, Preparation A. I. 0.3933 gram substance gave 0.2325 gram H20 22:6.57 per cent. H,and 0.7250 gram C02 — 50.42 per cent. C. II. 0.3693 gram substance gave 0.2182 gram H2Or2:6.55 per cent. H, and 0.6845 gram C022r 50.55 per cent. C. III. 0.3038 gram substance gave 44.1 cc. N at io° C. and 761.4 mm. pres- sure 22: 17.62 per cent. N. IV. 0.3067 gram substance gave 44.1 cc. N at 8.5° C. and 757-8 mm. pres- sure 2=: 17.47 Per cent. N. V. 0.5111 gram substance fused with K0H-j-KN03 gave 0.0406 gram BaSO< 22: 1.08 per cent. S. VI. 0.6773 gram substance fused with KOII + KNO3 gave 0.0440 gram BaSO., 2=0.89 Per cent. S. VII. 0.5265 gram substance gave 0.0102 gram ash 22: 1.93 per cent. 1 Carbon and hydrogen were determined by combustion in a current of oxygen, in an open tube, the vapors passing over a fairly long layer of coarsely granulated oxide of copper, a shorter layer of chromate of lead, and an anterior roll of freshly reduced metallic copper. Nitrogen was determined by combustion with oxide of copper after the Dumas method, while sulphur was estimated by Haminarsten’s modification of Liebig’s method.