PROCEEDINGS 
OF THE 
NATIONAL ACADEMY OF SCIENCES 
Volume I AUGUST 15, 1915 Number 8 
WEBER'S LAW AND ANTAGONISTIC SALT ACTION 
By Jacques Loeb 
ROCKEFELLER INSTITUTE FOR MEDICAL RESEARCH. NEW YORK 
Presented to the Academy, June 26, 1915 
L In a series of papers beginning in 1900 I have shown that: (a) 
It is necessary for the normal functions of Hving organs and organisms 
that the ratio of the concentration of antagonistic ions or salts Ci/C„ of 
the surrounding solution be kept within certain limits; if the value of 
this quotient becomes either too high or too low, life phenomena become 
abnormal and finally impossible.^ (b) The salts to be considered as 
antagonistic in this sense are in the first place those of univalent and 
bivalent metals and that therefore the most important critical quotient 
will generally be CNa + K/^Mg + ca- W There is also an antagonism be- 
tween the salts of bivalent ions such as Sr and Ca, and Mg and Ca.^ In 
the following discussion the antagonism between Na and K on the one 
hand, and Mg and Ca on the other will be solely considered. 
I further suggested that if the value of CJC^^, e.g., CNa+K/^Mg + Ca 
had once reached the lower limit required for the normal process of life 
phenomena the alternate reversible replacement of one of the two groups 
of ions by their antagonists in combinations with certain colloids (pro- 
teins or fatty acids) of the cells determined the alteration between activ- 
ity and rest of the organs or the organisms. 
This idea was carried further by Lasareff, who showed that from these 
data not only Nernst's law of electrical stimulation could be derived^ 
but also the phenomena of vision in weak light in which the effect 
depends solely on the bleaching of visual purple by the light. ^ 
Life phenomena as a rule take place in a medium whose composition 
and concentration undergoes little or no variation, such as sea water or 
blood serum, and the majority of organisms cannot stand any wide 
variation from this fixed standard. For such organisms only one value 
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