124 BOTANICAL GAZETTE [ AUGUST 
It is clear that a knowledge of the mere presence of a metal 
or other element in a solution does not allow one to drawa con- 
clusion as to its physiological action; it must also be known 4s 
to whether that element exists as an ion by itself or is combined 
with other elements to form a complex ion. If the addition of 
certain substances to a solution containing a physiologically 
active ion forms a complex ion of much less powerful action, it 
follows that these additional ingredients afford a means of 
reducing, so to speak, the physiological action of the simple 
ion. 
Although this work has thus far been carried out only with 
higher plants, investigations on bacteria that are being carried 
on in this connection at the Bacteriological Laboratory of the 
University of Wisconsin have already yielded results supporting 
the theory. Anyone inspecting Miquel’s table of the efficiency | 
of antiseptics in Sternberg’s ‘‘ Manual of Bacteriology,” and at 
the same time bearing in mind the theory of Arrhenius, although 
the concentrations are given in per cent. instead of chemical 
equivalents, will be able to see in it, only in rough outline a 
to be sure, the corroboration of the views here advanced: 
Experiments on animals are contemplated. on : 
It will be seen that a wide field for research along physi” 
logical lines opens up by applying to the field of biology a 
dissociation theory that has proved so fertile in chemistry 
physics. Further work in this direction, using the latest é 
best that the new physical chemistry has to offer, it is 10 
hoped will place our knowledge of the physiological actio® 
solutions of electrolytes on a better basis than the purely a 
ical one on which it has thus far rested. It does not seer ‘ 
much to expect that the effects of such study will soon be felt 
in agriculture and therapeutics, while bacteriological study Us 
sued from the standpoint of the new theory will yield import@ 
additions to our knowledge of antiseptics. ie 
UNIVERSITY oF WIsconsIN, MADISON, 
