ACTION OF ALKALIES ON PLANAR I A. 



animals. Buffering this water with borax proved effective a:~ a 

 means of maintaining it at a definite alkalinity but the borax 

 killed the worms in several days. Bubbling air through the flasks 

 in the hope of removing the carbon dioxide emanating from the 

 animals was not effective. When all of these methods failed, it 

 became necessary to use the ordinary well water and to change it 

 at frequent intervals. This proved fairly satisfactory. Boiling 

 this water to remove dissolved carbon dioxide was of some help. 

 The oxygen consumption of the worms was determined first in 

 untreated well-water, pH 7.6 to 7.8. The water was then made 

 alkaline to pH 9.0 with NaOH, decanted from the precipitate of 

 CaCO 3 when necessary, and the worms kept in such water for one 

 to two weeks continuously. The water was changed two or three 

 times in 24 hours. Between changes, it became somewhat less 

 alkaline but never fell below pH 8.6 throughout these long time 

 experiments. The rate of oxygen consumption was determined 

 every other day or every third day, always of course at pH 9.0. 

 Owing to the fact that the worms lost weight during the experi- 

 ment, because of starvation, for they were not fed throughout the 

 period of experiment, it was necessary to weigh them in order to 

 compare the rate of oxygen consumption at different intervals. 

 The figures therefore represent the cc. of oxygen consumed per 

 gram per hour. At the end of the experiment, the respiratory rate 

 in normal water was again tested. 



The results of three long time experiments which lasted one 

 week are given in Table III., and of three more \vhich lasted two 

 weeks, in Table IV. In Table III., the oxygen consumption was 

 determined first in normal water, then immediately in alkaline 

 water (ph 9.0), then every other day in the alkaline water, and 

 finally on the seventh day after the last test in alkaline water, again 

 immediately in normal water. As shown in the table there was a 

 marked acceleration of the respiratory rate during the latter part 

 of the stay in alkaline water; this acceleration was immediately 

 lost on return to untreated water, on the seventh day. The data 

 in Table IV. give a similar result : acceleration during the exposure 

 to alkaline water, immediate drop on return to untreated water. 



