June, 1922] IRWIN AND WEINSTEIN ACID FORMATION 
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begun, or whether it is due to the actual formation of such acids as a direct 
effect of the alcohol on the cells. It was found that when seedlings were 
killed in boiling water the presence of the acids could be demonstrated. 
Since enzymes are generally destroyed at this temperature, this experiment 
might seem to show that the acids were already present in the uninjured 
cells. However, in the case of oxidizing enzymes it has been shown that it 
is very difficult to destroy the enzymes by this method rapidly enough to 
prevent the oxidation completely. This is readily demonstrated in the 
Indian pipe {Monotropa uniflora), in which case it is difficult to destroy the 
enzymes rapidly enough by immersing the plant in boiling water to prevent 
the appearance of the black pigment. 
If the acids are normally present, it would be expected that they could 
be detected by killing the seedlings by liquid air. But when seedlings were 
exposed to liquid air and then crushed and extracted with cold water, there 
was no evidence of the presence of these acids. 
Seedlings were allowed to dry for one month on filter paper at room 
temperature and were then crushed and extracted with cold water, and 
the acids were found. The production of carbon dioxide by the dried seed- 
lings, after they were replaced in water, was found to be about one half 
the normal. Growth occurred when the seedlings were again soaked in 
water, but it was somewhat retarded. 
It is difficult to draw definite conclusions from these experiments, but 
it is possible that ethyl alcohol accelerates the decomposition of certain 
substances, forming an excess of intermediate products in the form of 
organic acids, until the concentration of the hydrogen ion (or of some other 
substance) increases to such an extent that any further decomposition into 
carbon dioxide and water is partly inhibited. The nature of the organic 
acids has not been determined, but further investigations may throw light 
on this point. 
The question may be raised whether the production of acids other than 
carbonic is due to the oxidation of the alcohol. Oxidation^ of alcohol by- 
higher plants has been reported. But in the experiments described above 
oxidation of ethyl alcohol does not seem to be the chief cause of the forma- 
tion of organic acids, because, as it was already shown, organic acids were 
formed when the seedlings were put in boiling water without having been 
treated with alcohol. 
It may be of interest to note the extreme complexity of the problems of 
revSpiration as indicated by the difference in the behavior of the radish seed- 
lings in ethyl alcohol, as contrasted with the behavior of Salvia in ether. ^ 
In the case of radish seedlings production of carbon dioxide is decreased 
and the acidity of the tissue apparently increases, while in the case of Salvia 
production of carbon dioxide is increased and the alkalinity increases. 
Loeb and Wasteneys^ showed that ethyl alcohol decreases the consump- 
^Zaleski, W. Biochem. Zeitschr. 69 : 283-289. 1915. 
^ Irwin, M, Jour. Gen. Physiol, i : 399-403. 1919. 
^Loeb, J., and Wasteneys, H. Jour. Biol. Chem. 14 : 517-523. 1913. 
