Walter Stiles 
142 
By direct tests of the cell sap of Nitella, Miss Brooks (1922) has 
shown that lithium, calcium and strontium ions enter the cells of 
this plant less rapidly from mixed balanced solutions than when 
presented singly. From determinations of the electrical conductivity 
of the sap of the same species Osterhout (1922 h) concludes that the 
nitrate ion rapidly penetrates the cells when sodium nitrate is pre¬ 
sented to the plant in pure solution, whereas when the sodium nitrate 
is balanced by the addition of calcium nitrate the rate of entrance is 
much slower. 
So far we have considered only the antagonism between inorganic 
salts, or, more correctly, between ions, for, as we have already seen, 
the ions of a salt may be absorbed to different extents. Antagonism 
has also been observed between inorganic salts and organic sub¬ 
stances such as dyes and alkaloids. Thus, von Eisler and von Portheim 
(1909) found the toxic action of quinine reduced by the presence of 
salts of sodium, calcium, magnesium and aluminium. 
Sziics (1912) examined particularly the antagonism between 
quinine hydrochloric and potassium nitrate, calcium nitrate and 
aluminium nitrate in the case of Spirogyra . The absorption of the 
quinine is made visible by the precipitation of tannin in the cells, 
while as a test of vitality, centrifuging the filaments was employed, 
the plasma and chloroplasts remaining fixed if the cells are dead, 
but not otherwise. Each of the three salts used was able to antagonise 
the toxicity and entrance of the quinine, the depoisoning effect 
increasing with the valency. 
That antagonism is actually due to the non-entrance of the toxic 
substances is indicated by the observation of Sziics on the toxic 
action of piperidine in presence and absence of various inorganic salts. 
For some unknown reason the absorption of piperidine is not hindered 
by inorganic salts, and the toxicity of the piperidine is increased 
rather than diminished by the addition of an electrolyte. 
Following up the work of Sziics on the antagonistic action of 
aluminium nitrate and quinine hydrochloride, Weevers (1914) ex¬ 
amined the depoisoning action of aluminium chloride towards a 
number of organic substances. The tissue used was red beet pa¬ 
renchyma, the exosmosis of the red pigment from the cells being 
taken as a criterion of toxic action. By this method it was shown 
that aluminium chloride could antagonise a number of organic poisons, 
namely, quinine hydrochloride, chloral hydrate, formaldehyde, amyl 
alcohol, ethyl alcohol, ether and chloroform. Antagonism was also 
observed between all these substances, except formaldehyde and ethyl 
