1905] TRUE & OGLEVEE—TOXIC ACTION OF POISONS 13 
bodies and all molecules do not seem to lend themselves with equal 
readiness to the adsorbing influence of solids (6). 
Applying this doctrine of adsorption to the results observed in 
our experiments, we find most points noted capable of explanation. 
The earlier experiments of NAGELI (2) with Spirogyra in distilled 
water obtained from copper containers and in other solutions con- 
taining extremely minute quantities’of heavy metals seem capable 
of satisfactory explanation. He observed that distilled water con- 
taining minute traces of metal could be rendered harmless by placing 
a quantity of some finely divided insoluble substance in the water. 
He used paraffin, graphite, filter paper, glass, and other substances, 
finding that thev interfered with the toxic action of the metals present. 
Doubtless the quantity of harmful ions or molecules adsorbed was 
so great as to reduce the number of ions or molecules in the free 
body of the solution below the harmful concentration. 
In the case of our lupines this same sort of action is also probably 
at the bottom of the ameliorating influence seen to attend the mere 
presence of a finely divided solid in solutions or strongly toxic agents. 
By drawing a portion of the ions or molecules of the poisonous sub- 
stance from the free body of the solution and by retaining these 
molecules or ions in a molecularly denser laver over their surfaces, 
the solids have removed from the free solutions enough of the toxic 
substance to decrease its poisonous properties. Since in the case 
of all of the insoluble substances used, paraffin excepted, the specific 
gravity is greater than that of water, the solids sink to the bottom of 
the culture vessel. As adsorption takes place, a somewhat gradual 
process (6), molecules and ions are renewed from the solution above, 
leaving it actually less concentrated than would be the case were the 
solutions not provided with the solid. As a result, when the roots 
of the test plant are introduced into the solution, it is found to have 
a decreased poisonous action. 
In the case of certain of the solids used in these experiments, it 
seems not at all impossible that a small degree of solution may have 
taken place. In experiments with crushed Bohemian glass this 
was doubtless the case, since it has been repeatedly demonstrated 
that such glass undergoes a slight solution even in.cold water. Unfor- 
tunately we were not able to make conductivity determinations to 
check up this factor. 
