abstracts: geology 421 



sorts of influence might operate at the same time, in equal or unequal 

 degree. The nine possible sources of variation are: (a) loss of oxalic 

 acid by volatilization, (b) decomposition of oxalic acid by water, (c) 

 decomposition of oxalic acid by sulfuric acid, (d) oxidation of oxalic 

 acid by the air, (e) incomplete oxidation of the oxalic acid, (f) liberation 

 of oxygen during the reaction, (g) incomplete reduction of the perman- 

 ganate to the manganous state, (h) presence of impurities in the oxalate 

 of either greater or less reducing power, and (i) formation of other prod- 

 ucts of the oxidation than carbon dioxide and water. Of these only 

 two appeared to be at all probable, viz: loss of oxygen and atmospheric 

 oxidation of the oxalic acid, and furthermore, only the first of these two 

 could be held in the light of all the experiments reported. 



If the main source of error is due to an oxygen loss the higher values 

 obtained in the various series must be taken as correct. On this basis 

 the following method of titration is recommended: in a 400 cc. beaker 

 dissolve 0.25 to 0.3 gram of sodium oxalate in 200 to 250 cc. of hot water 

 (80 to 90°) and add 10 cc. of 1:1 sulfuric acid. Titrate at once with 

 y^ KMn0 4 solution, stirring the liquid vigorously and continuously . The 

 permanganate must not be added more rapidly than 10 to 15 cc. per 

 minute and the last 0.5 to 1 cc. must be added dropwise with particular 

 care to allow each drop to be wholly decolorized before the next is added. 

 The solution should not be below 60° by the time the end-point is reached 

 The excess of permanganate used to cause the end-point color must be 

 estimated by matching the color in another beaker containing the same 

 bulk of acid and hot water. 



Under the above condition the agreement of duplicates should be at 

 least 1 part in 2000 ; and the variation from absolute accuracy of average 

 values is probably not greater than 0.05 per cent. Under other condi- 

 tions than those described it is possible to obtain correct results; but 

 by using the procedure recommended the difficulties of the titration are 

 reduced to a minimum. R. S. M. 



GEOLOGY. — The earthquakes at Yakutat Bay, Alaska, in September, 



1899. Ralph S. Tarr and Lawrence Martin. Professional 



Paper U. S. Geological Survey No. 69. 1912. Pp. 135, with maps, 



views, and sections. 



In September, 1899, the region around Yakutat, Alaska, was shaken 



by a series of severe earthquakes, attended by great changes in the level 



of the land and remarkable changes in the adjacent glaciers. 



The changes of level are the greatest recorded in historical times, the 



