MARIAN IRWIN 



401 



Experiments were made to determine whether exposure to ether 

 causes an increase in the consumption of oxygen. For this purpose 

 the apparatus shown in Fig. 2 was employed. The petals were placed 

 in a glass tube A, which was connected at one end (by tubes of glass 



500-1 % 



100 



35Mi. 



Fig. 1. Curves showing the respiration of Salvia petals first in tap water (hori- 

 zontal line) and then in 7.3 per cent ether. Time is reckoned from the beginning 

 of exposure to ether. The respiration of a control in tap water is shown by the 

 broken line. The normal rate (which is taken as 100 per cent) corresponds to a 

 change in pH value from 8.0 to 7.7 in 193 seconds. Temperature, 20° ± 1°C. 

 Probable error less than 1.7 per cent of the mean. Curve A, average of six ex- 

 periments; Curve B, average of four experiments. 



Fig. 2. Apparatus for the determination of oxygen consumption. Petals were 

 placed in A; by alternate compression of the bulbs C and E the air in the appara- 

 tus was made to circulate. At the close of each experiment the tube D was 

 removed and its contents were analyzed for oxygen. 



