1905] TRUE & OGLEVEE—TOXIC ACTION OF POISONS 17 
_ development. While it may not be practicable in all cases to work 
out all features of this generalized scheme with the very toxic salts 
tested, the most striking points hold. 
It is now not difficult to understand a number of phenomena seen 
in results presented above. By preliminary tests not here detailed 
a concentration of each substance was found which practically sup- 
pressed growth and gave a physiological starting point from .which 
to follow out the action of the poison along the line of progressive 
dilution and also in the presence of solids. In most cases, the solu- 
tions of the toxic compounds lie in the degree of concentration marked 
by a depressant phase of physiological action. As molecules or ions 
are removed by adsorption, the effect is virtually one of dilution, and 
the depressant action becomes less marked; or when adsorption 
removes a sufficient portion of molecules or ions to bring the solution 
into the accelerant phase, instead of the depressant, an acceleration 
above the control rate appears. The degree of acceleration depends 
on whether adsorption withdraws such a proportion of the molecules 
or ions as will leave the solution in its maximum accelerant phase or 
above or below this. It should also be borne in mind that at least 
theoretically, after the depressant phase has been passed, two quite 
differing concentrations lying on either side of the maximum may 
give the same physiological result. Experiments with solutions further 
diluted will enable one to decide on which side of the maximum the 
result may lie. Theoretically, a careful study of a long series of 
slightly differing concentrations should enable us to ascertain rela- 
tively how much of a given poison is removed by a given quantity 
of an adsorbing agent. This can hardly be attempted with justice 
from the results at hand, since they were obtained under conditions 
rendering the necessary accuracy of experimentation impossible. 
Nevertheless, I believe some rough idea may be obtained from the 
work presented. It will suffice to point out a few instances, since 
it is manifestly impossible to point out the application of this scheme 
to all of the results obtained. 
In the case of the mercuric chlorid (p. 5) —— is manifestly 
low in the depressant phase of its action, the introduction of the sand 
carrying it a manifest step upward, though leaving the situation 
