Geology and Natural History. 287 



a solution is obtained from wliich the tin may be precipitated 

 with hydrogen sulphide. It does not appear that tlie method 

 has been tested by quantitative experiments, but the results are 

 interesting in indicating the possible interference of hydrofluoric 

 acid in analytical operations where tin is present. — Zeitschr. 

 anorgan. Chern., Ixvii, 315. h. l. w. 



4. Manufacture of Ethyl Alcohol from Sawdust. — It is staled 

 that ethyl alcohol — not methyl, or wood alcohol— is being made 

 fi'om sawdust on a large scale in France, and that the process will 

 soon be put into operation in the United States and Canada. 

 The process was invented by Dr. Alexander Classen of Aachen, 

 Germany, and consists in heating the sawdust under pressure 

 with water and sulphurous acid, thus converting the cellulose into 

 fermentable sugar. The sulphurous acid is then drawn off, a 

 certain amount of acetic acid formed at the same time is distilled 

 off and saved, and the liquor separated from the residue is neu- 

 tralized, fermented, and distilled. It is claimed that the insoluble 

 residue of the process may be used as food for stock, and that 30 

 gallons of alcohol may be made from a ton of sawdust. — Cheni. 

 News., cii, 41. h. l. w. 



II. Geology and Natural History. 



1. The California Ear thquaJce of April 18, 1906. Report of 

 the State Earthquake Znvestigation Co^ninission. Volume II. 

 The Mechanics of the Earthquake ; by Harby Fielding Reid. 

 Pp. viii, 192 ; with 2 plates and 62 figures. Washington, D. C, 

 1910. Published by the Carnegie Institution. — This second vol- 

 ume of the report of the California Earthquake is of great scien- 

 tific interest.* It consists of a first part on the phenomena of the 

 megaseismic region, a second part on the instrumental records of 

 the earthquake, and an appendix on the theory of the seismo- 

 graph. The purpose of the review will be to give a summary of 

 some of the conclusions of general interest contained in the first 

 two parts. 



In discussing the permanent crustal displacements resulting 

 from the earthquake, it is noted that the shifting at the San 

 Andreas fault line amounted to about 6 meters, the southwestern 

 side moving northwest. The geodetic surveys carried on from 

 1874-1892 and in 1906-1 90*7 showed that the Farallon Islands, 

 37 kilometers southwest of the fault, had moved northward 1*8 

 meters. The movement of the latter Reid does not regard as 

 accomplished at the time of the shock, but as going forward 

 gradually and accompanying the accumulation of the stresses 

 which were finally relieved at the time of fracture. That is, two- 

 thii-ds of the stress which caused the rupture had already accumu- 

 lated 25 years ago, and 50 years ago, as shown by the surveys of 



* See G. K. Gilbert, this Journal, xxvii, 48. 



