The heat of combustion of vegetable proteins / by Francis G. Benedict and Thomas B. Osborne.

  • Benedict, Francis Gano, 1870-1957.
Date:
[1907]
Catalogue details

Licence: In copyright

Credit: The heat of combustion of vegetable proteins / by Francis G. Benedict and Thomas B. Osborne. 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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    17 THE HEAT OF COMBUSTION OF VEGETABLE PROTEINS. By FRANCIS G. BENEDICT and THOMAS B. OSBORNE. (From the Chemical Laboratory of Wesleyan University and the Laboratory • of the Connecticut Agricultural Experiment Station.) (Received for publication, March 16, 1907.) Very few determinations of the heat of combustion of vege- table proteins are to be found in the literature. The earliest appear to be those made by Danilewsky,1 who found for “ Pflan- zen-fibrin” 6231, for legumin 5573 and gluten 6141 calories per gram. As these determinations were made according to Stohmann’s method at a time when this method was not perfected and as numerous precautions, which later were found to be important, were not considered, Stohmann2 made new determinations of the heat of combustion of several proteins, among which were the crystallized globulin of the squash seed, prepared by Grubler, for which he found 5598 calories, and conglutin, which gave 5362 calories per gram. Berthelot and Andre,3 using the Berthelot bomb found for “Vegetable fibrin” 5837, for crude gluten 5995 calories per gram. Stohmann and Langbein,4 next determined the heat of combus- tion of various carefully prepared proteins using the calorimetric bomb of Berthelot. Most of the preparations were made by Grubler and before combustion were protractedly extracted with ether. The substances were burned in the air dry state and the results calculated to a water and ash-free basis. They found for “ Pflanzen-fibrin” (glutenin of wheat) 5942, for legumin from white beans (phaseolin) 5793, for the crystallized globulin of squash seed 5672, and for conglutin from lupines 5479 calories per gram. No other determinations of the heat of combustion of vegetable proteins are known to us. 1 Danilewski: Centralbl. f. d. med. Wissensch., xix, pp. 465 and 486, 1881. 2 Stohmann: Journ. f. prakt. Chem., xxxi, p. 273, 1885. 3 Berthelot and Andrd: Ann. de chim. et de phys., xxii, p. 25, 1891. 4 Stohmann and Langbein: Journ. f. prakt. Chem., xliv, p. 336, 1891.