Mercers' company lectures on recent advances in the physiology of digestion : delivered in the Michaelmas term, 1905, in the Physiological Department of University College, London / By Ernest H. Starling.

  • Starling, Ernest Henry, 1866-1927.
Date:
1906
Catalogue details

Licence: Public Domain Mark

Credit: Mercers' company lectures on recent advances in the physiology of digestion : delivered in the Michaelmas term, 1905, in the Physiological Department of University College, London / By Ernest H. Starling. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    for twenty feet, but will enable him to attain the top. Or we might imagine a stone perched at the top of a high hill. The passive resistance of the system, the friction of the stone and its inertia, will tend to keep it at rest, even though it be on a sloping surface and, therefore, tending to slide or roll to the bottom. If, however, it be rolled to the edge, to a point where there is a sudden increase in the rapidity of slope, it may roll over, and, having once started its downward course, its momentum will carry it to the bottom. The amount of energy set free by the stone in its fall will not vary whether the course be a uniform one, or whether it falls over a preci- pice at one time and rolls down a gentle slope at another. It is evident that, by a mere alteration of the slope or, in the case of a chemical reaction, of the velocity of part of its course, a change in the system may be initiated and brought to a conclusion which, without this alteration, would never take place. We have, therefore, to inquire in the case of enzymes or ferments how far their action is to be explained by surface l^henomena, or by the formation of intermediate compounds between the ferment and the substance it acts upon (w^hich is generally known as the substrate). This discussion we may defer until the next lecture. c2