300 COX. 
TABLE II.—The deterioration in calorific value of coals stored in air and 
im oxygen. 
Calorific value of the pure | Lowering of calo- 
coal. rific value. 
coal 
0. After 
Original ae e | Storage Stored Stored 
sample. | 5 air, | 2 Hee in air. Sean 
. Per cent. | Per cent. 
1 7, 130 _ 7, 042 7, 034 1.2 1.3 
2 6, 893 6, 836 6, 865 0.8 0.4 
3 7, 189 7, 089 7, 069 1.4 1.7 
The gases above the coal at the end of the storage period 
were analyzed as follows: 
TABLE III.—Com~position of the gases above the coals stored in air.* 
Volume percentages. 
oat 
oO. 
Carbon 2 Remain- 
dioxide. Oxygen. der. 
1 1.5 18.7 79.8 
: 2 0.2 17.7 82.1 
3 1.3 15.8 82.9 
4 2.2 15.9 81.9 
5 3.2 15.7 81.1 
———| 
8 The gases above the coal were frequently replaced with air freed from carbon dioxide 
to insure an adequate supply of oxygen. Therefore, these results do not show the total 
amount of carbon dioxide evolved, but show its presence and the exact composition of the 
gas above each coal when it was removed for analysis. 
TABLE IV.—Composition of the gases above the coals stored for nine months 
im commercial oxygen. 
| Volume percentages. 
Coal 
Carbon! Remain- 
dioxide. Oxygen. der.® 
il 6.0 22.9 71.1 
2 1.6 19.5 78.9 
3 2.6 14.2 83.2 
4 4.5 17.9 77.6 
on 
4.9 14,4 80.7 | 
® Unabsorbed in alkaline pyrogallol. Traces of carbon monoxide were detected, but hydro- 
gen, methane, formaldehyde, formic acid, or hydrogen peroxide were not recognized by 
ordinary means of identification as reaction products, although it is probable that some or 
all of them were present in small quantities. 
