DOI article:
Flexner, Simon: The Rockefeller Institute for Medical Research, New York
DOI Page / Citation link:https://doi.org/10.11588/diglit.57254#0508
probably explainable by the movement of potassium ions. An application of a rather
concentrated potassium Chloride solution sets up a series of negative variations.
These studies make it evident that protoplasm performs an extraordinary feat
in spreading a very thin, nonaqueous layer between two aqueous ones, thus
forming a semi-permeable surface which permits the manifestation of colloidal
properties and all the bio-electric phenomena.
In connection with these physiological experiments, physicochemical work,
chiefly of an electrochemical nature, has been carried out. MacInnes has studied
strong and weak electrolytes, devising improved methods, such as a more accurate
Wheatstone bridge, and an apparatus for studying the moving boundary observed
when a current passes through the junction between two suitable Solutions. Sur-
prisingly simple relations have been found, showing that the contribution of a given
ion to the conductivity is offen the same in quite different combinations.
An improved glass electrode has been developed, and an apparatus has been
designed for its use when only a drop or two of fluid is available. This work has led
to a tentative theory of the glass electrode which has a direct bearing on the theory
of the protoplasmic surface. A revision of the pH scale is also in progress.
Weak electrolytes have been studied by substituting such atoms as halides in
various positions in long carbon chains. A remarkably simple relation has been
found between the ionization constant and the number of carbon atoms separating
the substituted atom from the carboxyl group.
490
concentrated potassium Chloride solution sets up a series of negative variations.
These studies make it evident that protoplasm performs an extraordinary feat
in spreading a very thin, nonaqueous layer between two aqueous ones, thus
forming a semi-permeable surface which permits the manifestation of colloidal
properties and all the bio-electric phenomena.
In connection with these physiological experiments, physicochemical work,
chiefly of an electrochemical nature, has been carried out. MacInnes has studied
strong and weak electrolytes, devising improved methods, such as a more accurate
Wheatstone bridge, and an apparatus for studying the moving boundary observed
when a current passes through the junction between two suitable Solutions. Sur-
prisingly simple relations have been found, showing that the contribution of a given
ion to the conductivity is offen the same in quite different combinations.
An improved glass electrode has been developed, and an apparatus has been
designed for its use when only a drop or two of fluid is available. This work has led
to a tentative theory of the glass electrode which has a direct bearing on the theory
of the protoplasmic surface. A revision of the pH scale is also in progress.
Weak electrolytes have been studied by substituting such atoms as halides in
various positions in long carbon chains. A remarkably simple relation has been
found between the ionization constant and the number of carbon atoms separating
the substituted atom from the carboxyl group.
490