966 



SCIENCE 



[N. S. Vol. XXV. No. 651 



of instances, thougli in the vast majority of 

 cases tlie plant material seemed to have under- 

 gone little, if any, appreciable drifting. The 

 great extent and regularity in thickness, in- 

 cluding partings and benches, of the Pitts- 

 burg bed in the Appalachian trough appeared 

 not to find a completely satisfactory explana- 

 tion in either the transportation or the peat- 

 bog theories. Eeferring to the fact that the 

 process of coal formation is marked chiefly 

 by the progressive deoxygenation of the vege- 

 table matter, especial attention was directed 

 to the most important role played by anerobic 

 bacteria in the decomposition of the plant 

 tissues and their incipient coalification. 

 Though it is not yet determined how far 

 bacterial action may have gone in changing 

 vegetable matter into bituminous coal, etc., 

 the function of these deosygenating organisms 

 in accomplishing the primary stages of coal 

 formation, including at least the breaking 

 down of the vegetable hydrocarbons and the 

 development of the fundamental jelly, is now 

 rapidly gaining acceptance on the part both 

 of geologists and of chemists. Concerning 

 the successive development of lignites, bitu- 

 minous coals and anthracites there still re- 

 main radical differences of opinion, it being 

 maintained by many, including several paleo- 

 botanists, that the higher grades of coals have 

 never passed through a i>eaty, lignitic or other 

 lower stage. The solution of this problem, 

 whose principal point is the origin of the 

 bituminous coals, is awaited with the greatest 

 interest. The speaker urged that the cause of 

 anthracitization in the Eastern Appalachian 

 regions rested primarily not in local folding, 

 but in the deeper-seated metamorphism due to 

 the great post-Carboniferous Atlantic thrust. 

 This is shown by the progressive devolatili- 

 zation of the coals in passing eastward across 

 the Appalachian basins. The folding was 

 merely incidental and relieving. 



Another group of problems involves tie 

 determination of the very intimate and im- 

 portant relations existing between the kinds 

 of original contributary organic matter and 

 the kinds and qualities of the resultant fuels. 

 It is known that certain groups of coals owe 

 their principal distinctive features to the na- 



ture of their original constituents. In this 

 connection the speaker suggested that the 

 coking property in some of the Appalachian 

 coals was probably due to a combination of 

 ' sapropelic ' (fatty) or strictly bituminous or- 

 ganic matter, with the ordinary ' humic ' 

 (jetty, brilliant) or so-called ' bituminous ' 

 coal-forming material, which is largely com- 

 posed of the remains of the higher types 

 of plants. 



Emphasis was put on the urgent need for 

 new and more complete experiments in syn- 

 thetic coal-making, concerning which the 

 testimony of previous experimenters is highly 

 conflicting. Such experiments carried out 

 with new and more adequate methods and 

 equipment, comparable to those employed in 

 the Geophysical Laboratory of the Carnegie 

 Institution, would not only furnish most valu- 

 able data relating to coal transformation, but 

 they would also probably furnish a conclusive 

 answer to the question of the development of 

 bituminous coals or anthracites through peat, 

 lignite, or subbituminous coal stages. 



The Jamaica Earthquake : Mr. J. W. Spencer. 

 Jamaica is separated from the volcanic and 

 earthquake zone of the Windward Islands by 

 the broad deep basin of the Caribbean Sea, 

 nearly 1,000 miles across, and from that of 

 Central America by about 600 miles. Jamaica 

 is on a plateau connecting this latter region 

 with Haiti; but much the greater part of the 

 intervening distance between the Central 

 American volcanic and earthquake zone and 

 the island is occupied by low plains, or these 

 only slightly submerged beneath the sea, and 

 crossed by one relatively narrow channel 

 reaching to a depth of nearly 3,000 feet. The 

 trend of this Jamaican ridge being at right 

 angles to the lines of the earthquake actions 

 of the two ends of the Caribbean Sea, it would 

 seem that the seismic effects could not have 

 any relationship with others of the region so 

 far away. Moreover, Jamaica is not volcanic, 

 with only the remnants of one Pliocene vol- 

 cano upon the northern coast. On its south- 

 ern side, which is mostly a plateau from one 

 to two thousand feet high, capped by white 

 Oligocene limestones much denuded, a coastal 



