294 
PHYSICS: H. B. LEMON 
Figure 5 shows continuation of the attempt for the second time to destroy 
the activity. Repeating curve 10 of the preceding and outgassing 
Eleventh. 0.5 hours at 950°C. 
Twelfth 1.5 hours at 985°C. 
the activity is again reduced. Recovery is now as before sluggish and was 
not carried to completion. 
Thirteenth 3.0 hours at 650°C. 
Fourteenth 8.0 hours at 625°C. 
Fifteenth 12.0 hours at 645°C. 
Sixteenth 1.5 hours at 650°C. 
Seventeenth 14.0 hours at 650°C. 
The characteristic form of the family of curves shown is undoubtedly of 
generic quality. These curves have been reproduced on a wide variety of 
samples of cocoanut shell charcoal many times; and when the results are 
assembled exhibit almost every degree of gradation from a central, closely 
linear (after the first minute) relationship. Similar experiments on pure gases 
rather than air are in progress in the hope of simplifying this family of curves 
somewhat so as to obtain an interpretation expressible in analytic form. 
Two hypotheses have been advanced for these phenomena. One ascribes 
the changes in the sense of increased activity to the gradual distillation out 
of the material of heavy nonvolatile hydrocarbons, many of which in the 
form of tars and gums come off during the initial carbonization. The other 
is based on the conception advanced by Miss Ida Homfray^ that these phe- 
