1908.] Agents in the Oxidation of Amorphous Carbon. 249 
First, as regards the evolution of COs Several flasks were prepared 
containing small fragments of the dried peat, soaked with water, and 
sterilised by discontinuous boiling. A stream of air, carefully freed from 
all trace of COs, drawn through the research-flasks and then through baryta 
water, failed to exhibit any trace of this gas, even after many days. When 
this result was well established, some of the research-flasks were inoculated 
with bacteria, and within a day the cloudy precipitate appearing in the 
baryta showed that a considerable amount of CO, had been evolved as 
the result of bacterial action, and a copious precipitate continuing to be 
deposited indicated that a somewhat vigorous oxidation was taking place. 
Secondly, to measure any rise of temperature due to oxidation, the 
experiments with the double-walled vacuum-flasks, the thermopile and 
galvanometer, were again set in operation, substituting only peat for 
charcoal. The results were completely in accordance with those noted for 
the charcoal, except that, as might be expected from the nature of the 
substance and the consequent greater evolution of COs, the oxidation was 
more vigorous and a greater rise of temperature was recorded. It was | 
found that the inoculated flask maintained a temperature of 1°05 C. above 
the incubator for a considerable time. 
These expervments clearly show that when peat is exposed to damp air and to 
the action of switable organisms wt decays rapidly, with the evolution of COs, 
accompanied by a rise in temperature. 
Coal. 
The investigation of ordinary household coal presented many difficulties, 
chiefly on account of problems connected with sterilisation and the presence 
of occluded gases, and I have not been able to entirely overcome some 
special difficulties of the case. Obviously the inflammable gases contained 
within the coal and its combustible nature rendered sterilising by dry heat 
an impossibility. 
For the purpose of experiment the coal was taken from the centre of a, 
large piece to avoid contamination with foreign matter ; it was pounded and 
passed through sieves similar to those used for the charcoal, and then 
sterilised in the same manner by passing steam through the Cloéz research- 
flasks and subjecting the coal to a partial vacuum. The titrations showed 
that the flasks which were inoculated with bacteria gave off some 10 milli- 
grammes of CO: in excess of the non-inoculated flasks during the course of 
three weeks, but even with the strictest precautions traces of CO», were 
found in the non-inoculated flasks, owing to the escape of this gas from the 
occluded state. It was this difficulty which first suggested that the measure- 
