June, 1922] IRWIN AND WEINSTEIN ACID FORMATION 
279 
With iM alcohol the production of carbon dioxide by seedlings remains 
unchanged for the first hour, as shown by figure i, curve B. With 2M 
alcohol there is a slight decrease during the first hour (fig. i, curve C). 
With 4.M solutions, a great decrease takes place in about twenty minutes 
(fig. I, curve D). This change is irreversible. 
The fact that death is often accompanied by an increase in the produc- 
tion of CO2 might lead to the suspicion that such an increase also occurs 
in the case of alcohol. 
With the apparatus used for the present investigation, the first reading 
cannot be taken within ten or fifteen minutes after the immersion of the 
seedlings in the test solution. For this reason it might be supposed that an 
increase followed by a decrease may have taken place during the first fifteen 
minutes of the experiment. If an increase really occurred then, it seems 
probable (on the basis of other experiments) that it would persist for a time 
after removal from the alcohol. In order to test this, the seedlings were 
put in 4.M alcohol, removed and washed for half a minute in running water, 
and then put into the apparatus with 3 cc. of tap water, after which the 
readings were made. Exposure of radish seedlings to the alcohol for three 
minutes brought about no change in the rate of respiration, while there 
was a slight decrease after an exposure of five minutes, and a greater decrease 
after exposures of seven and ten minutes, as shown in figure 2, curves B, 
uKj-^ ^ ^ 
0 30 60 MiNS. 
Fig. 2. Curves showing the effects of 4.M ethyl alcohol on the production of carbon 
dioxide by radish seedlings. Curve A shows the rate of respiration in tap water (without 
exposure to alcohol). Curve B shows the rate after the seedlings have been exposed to 
the alcohol for 5 minutes and then replaced in tap water; curve C, exposed for 7 minutes; 
curve D, for 10 minutes. Each point represents the average of 12 experiments. Probable 
error of the mean is less than 4 percent of the mean. 
