On the digestive ferments and the preparation and use of artificially digested food : being the Lumleian lectures for the year 1880, delivered before the Royal College of Physicians / by Wm. Roberts.

Date:
1880
Catalogue details

Licence: Public Domain Mark

Credit: On the digestive ferments and the preparation and use of artificially digested food : being the Lumleian lectures for the year 1880, delivered before the Royal College of Physicians / by Wm. Roberts. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    restored to the warm cliamber and re-examined at the expiration of seven hours. No. 4 no longer gave the shghtest reaction with iodine, but Nos. 1, 2, and 3 showed only slight signs of fmother altera- tion, and were returned to the warm chamber. At the end of 48 hours from the commencement of the experiment, No's. ], 2, and 3 were examined again. No. 1 showed a strong blue coloration with iodine, and also a strong reaction of erythro-dextrine. No. 2 no longer gave any blue tint with iodine, but it exhibited an intense erythro-dextrine reaction. No. 3 only gave a yellowish brown reaction with iodine of moderate intensity. After a further sojourn in the warm chamber of seventy hours the contents of the three phials were not found to be sensibly altered—they gave exactly the same reactions as before. It was evident that in these phials the diastatic action had run its course to an end within the period of forty-eight hours, and that the solutions had then come to a state of rest—^the ferment had liberated all its energy—the limits of its power had been reached— and the task allotted to it was left unfinished. Nevertheless it had accomplished an amount of work which, considering its infinitesimally minute mass, appears marvellous. We shall now endeavour to measure approximatively the amount of this work as indicated by the above experiments. The original pancreatic extract, when evaporated to dryness in a water-bath, was found to leave a