Osmosis experiments with living and dead membranes / by E. Waymouth Reid.

  • Reid, E. Waymouth.
Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: Osmosis experiments with living and dead membranes / by E. Waymouth Reid. 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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    fully, and it is my intention to pursue the subject further, especially •with reference to the mucosae of the alimentary carnal. So far as the skin of the frog is concerned the following conclusions seem warrauted— 1. The normal direction of easier osmotic transference of fluid through the living skin of the frog is in the direction from the outer towards the inner surface. 2. The transference of fluid through the skin in the above direc- tion is intimately associated with the physiological condition of its tissues; conditions or agents tending to depress vitality diminish the transfer in the normal direction, while stimulants give rise to augmen- tation. 3. The cause of the easier transference of fluid from the outer towards the inner surface, is probably to be found in the existence of an absorptive force dependent on protoplasmic activity, and comparable to the secretive force of the gland cell. 4. In consequence of the absorptive force acting from without inwards, an alteration of the relations of the surfaces of the skin to the two fluids used in an osmosis experiment modifies the rapidity of the transfer of fluid from one to the other side of the membrane, according as the force exerted by the living tissues is with or against the osmotic stream. [The expenses of this research were in part defrayed by a grant from the British Medical Association.] DESCRIPTION OF TRACINGS. Tracing (1) is from a record on smoked paper. Tracings (2), (3), (4) and (5) are from the Differential Recording Osmo- meter. Tracings (6), (7), (8), (9), (10), (11) and (12) are from the Double Recording Osmometer. In all tracings except (1) the time traciug marks hours. In the tracings from the differential instrument, 1 mm. deflection above the zero line, i.e. towards the time tracing, denotes a difference of -91 cubic millim. between the volumes of fluid passing through the membranes on the pair of discharging osmometers, in favour of the right osmometer; the same deflection below zero or away from the time tracing indicates an excess of 91 cub. mm. in favour of the left osmometer. In tracings (2), (3) and (4), 95 sq. mm. of skin were exposed on each osmometer; in tracing (5) 190 sq. mm. were used. Irregularities in the line of the tracing are the result of viscosity of the oil used.