Proteins : lectures given in the United States of America in 1924 / by S.P.L. Sørensen.

  • Sørensen, S. P. L. (Soren Peter Lauritz), 1868-1939.
Date:
1925
Catalogue details

Licence: In copyright

Credit: Proteins : lectures given in the United States of America in 1924 / by S.P.L. Sørensen. Source: Wellcome Collection.

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    has given rise. I will merely touch on a single important point, the question of the influence of the electrolytes present on the osmotic pressure of the colloid solution. It was Don- nan's1 theoretical treatment of this question, and the theory formulated by him on a sure thermodynamic basis, which first rendered possible the elucidation of this point, to which the comprehensive researches of Jacques Loeb,2 whose early death is greatly to be deplored, greatly contributed. The essence of Donnan’s theory is best illustrated by a simple example. Let us take a solution containing both diffusible and indiffusible ions, a solution of protein chloride, Prot-Cl, with the chlorine normality N. This we place in a vessel with semipermeable membranes, a collodion tube, sur- rounded by an electrolyte solution, dilute hydrochloric acid of normality N. The collodion membrane may be denoted schematically by a vertical line, and we may use the terms “inside solution” and “outside solution” for the solution in- side and outside the tube respectively. We can then, assum- ing the dissociation to be complete, express such a system as follows: Inside Outside cr cr Prot+ H+ Donnan now shows by a simple thermodynamic considera- tion that this system cannot be in equilibrium, but that there will be a diffusion of hydrochloric acid from the outside solu- tion to the inside solution until we have, in the state of equili- brium, the conditions of the following equation fulfilled: 1 Zeitschr. f. Elektroch. 17:572 [1911]. 3 Proteins and the Theory of Colloidal Behavior [1922]. See also Niels Bjer* rum: Zeitschr. physik. Chem. 110 [1924].