312 COX. 
probably may be as effectually avoided by the use of bunkers, 
with tight floors and sides and fairly close-fitting covers, filled 
with carbon dioxide as by storage under water. The following 
experiments show the effectiveness in preventing deterioration 
by the exclusion of air through inert gases. Two 250-gram 
samples of each coal, one in nitrogen and the other in carbon 
dioxide, were stored for about nine months in 10-liter bottles at 
about 30° C. in an ordinary room lighted by diffused sunlight. 
TABLE X.—Analyses and calorific values of Philippine coals stored in 
nitrogen and in carbon dioxide. 
After storage in nitro- | After storage in carbon 
Original sample. care ote! 
Coa | 3 | 
No. re Volthle Fixed se “is “ae 
oi8- combus- alo- 018- . .O18- - 
fae, | ae crt Ash. | 45 eae || aime. Ash. |Calories. Rares Ash. Calories.! 
matter. ® 
Per ct.| Per ct. | Per ct. | Per ct. Per ct. | Per ct. | Per ct. | Per ct. 
1 5.90 46.30] 40.08 1.712 6, 159 5. 48 7.66 6, 227 5.56 6.97 | 6,249 
2 8.61 40.67 | 46.55 4.17 6, 012 8.46 4.05 6, 050 7.68 4.91 | 6,057 
3} 11.55 37.48 | 46.95 4.07 6,066 | 10.39 3.81 6,199 | 10.86 3.88 | 6,161 
a After the method of Cox, This Journal, Sec. A (1907), 2, 41. 
b Each analysis shows somewhat less ash than the ordinary coal from the same source 
because of the way in which the samples were prepared. 
¢ Average of three closely agreeing, independent determinations. 
The above results calculated to the uniform basis of pure 
coal show that there was no deterioration on storage. 
TABLE XI.—The calorific value of coals stored in nitrogen and in carbon 
dioxide. 
A Variation from 
Calorific valueof thepurecoal.2, original sample 
in calories. 
Coal 
oO. 1 
3 After After 
Original | storage |storagein) Stored in peered 
sample. | in nitro-| carbon |nitrogen. dioxide 
gen. dioxide. dD 
1 7, 180 7, 168 7, 144 +38 +14 | 
2 6, 893 6, 914 6, 929 +21 +36 
3 7, 189 7, 225 T, 226 +36 +387 
® An interesting comparison is that of Table XI with Table II from which it will be 
seen that the coal stored in air has a calorific value about 2 per cent less than that stored 
in either of the above inert gases. 
Table XI shows an increase in calorific value during storage. 
I can not explain this, but it is probable that it is due to the 
evolution of carbon dioxide rather than to experimental error. 
That such change does take place in a coal which has absorbed 
ee 
