[Illustration: German Charcoal. ×200.] [Illustration: FIG. 73.—Charcoal from Spruce Wood.] COMPARISON OF CHARCOAL The following table shows a comparison of charcoals from different sources. The method of activation was identical and the times of treatment were those approximately giving the highest service time. The results against chloropicrin, therefore, represent roughly the relative excellence of the charcoal obtainable from various raw materials, using this method of activation: COMPARISON OF VARIOUS ACTIVE CHARCOALS ACTIVATED IN LABORATORY -----------------+-----------------+---------------+---------------- | | | Accelerated | Apparent |Steam Treatment| Chloropicrin | Density | at 900° | Test Results Base Material +-------+---------+----+----------+--------+------- |Primary|Activated|Time| Weight | Weight |Service |Carbon | Carbon |Min.| Loss |Absorbed| Time | | | | Per Cent |Per Cent| Min. -----------------+-------+---------+----+----------+--------+------- Sycamore | 0.158 | 0.080 | 18| 53 | 41 | 7.3 Cedar | 0.223 | 0.097 | 60| 88 | 78 | 16.0 Mountain mahogany| 0.420 | 0.236 | 60| 44 | 32 | 16.3 Ironwood | 0.465 | 0.331 | 60| 44 | 31 | 20.8 Brazil nut | 0.520 | 0.316 | 120| 71 | 46 | 32.2 Ivory nut | 0.700 | 0.460 | 120| 70 | 48 | 47.0 Cohune nut | 0.659 | 0.502 | 120| 48 | 51 | 53.4 Babassu nut | 0.540 | 0.322 | 210| 68 | 85 | 58.7 Cocoanut | 0.710 | 0.445 | 120| 60 | 61 | 58.4 Cocoanut | 0.710 | 0.417 | 180| 75 | 72 | 64.4 -----------------+-------+---------+----+----------+--------+------- BRIQUETTED MATERIALS -----------------+-------+---------+----+----------+--------+------- Sawdust | 0.542 | 0.365 | 120| 66 | 53 | 40.0 Carbon black | 0.769 | 0.444 | 240| 64.3 | 53 | 50.5 Bituminous coal | 0.789 | 0.430 | 165| 61 | 58.3 | 46.8 Anthracite coal | 0.830 | 0.371 | 480| 81 | 53 | 40.7 -----------------+-------+---------+----+----------+--------+------- “In conclusion, it will be of interest to compare the charcoals manufactured and used by the principal belligerent nations, both with one another and with the above mentioned laboratory preparations. Data on these charcoals are given in the following table: