L. G. M. BAAS BECKING AND H. C. HAMPTON 27 1 
Cc. extract 
A-B 
A-B Calculated for 
E X (A-B) = 1.5 
Ex (A-B) 
4 
0.38 
3 
0-5 
Not measurable 
2 
0.75 
I 
1-5 
0.5 
I* 
3 
0.2 
7 
7.5 
1.4 
0.1 
15 
15 
1.5 
0.05 
32 
30 
1.6 
* Out of place. 
V. 
There is still one assumption which we have not proved. How do we 
know that the reaction is finished at the point C of our curve (fig. 2), where 
Fig. 5. Autogram showing latency times. 
the curve becomes assymptote to the time axis? To determine this we 
have only to calibrate our flask. If the volume of the container to the 
level of the mercury is Vi, the volume of the peroxide Vh, and that of the 
extract Ve, the remaining volume before the beginning of the reaction will 
be Vi — '(Vh — Ve). After the liberation of oxygen the mercury is forced 
down a cm., the volume of i cm. to be Vc cc, so the volume after the reaction 
will^be 
Vi = (Vh + Ve) + aVe. 
If the temperature is constant during the experiment, we can use the simple 
formula of Boyle. If the pressure before the experiment be H cm. mercury, 
it will be (H + 2a) after the reaction. We get for the volume after the 
