682 



SCIENCE 



[N. S. Vol. XXXVI. No. 933 



cultural Experiment Station in Kodiali were 

 collected.'' The samples here described were 

 submitted to this bureau through the Office of 

 Experiment Stations and a mineralogical ex- 

 amination of them was made. 



Sample No. I. is light in color and rather 

 coarse. It represents the first fall, which 

 reached a depth of about six inches. There 

 are present indeterminable feldspars, a slight 

 amount of muscovite and a few apatite in- 

 clusions. Glass constitutes the larger part of 

 the mass. The refractive index of this glass 

 is below 1.50, thus indicating that the silica 

 content is above 72.65 per cent. 



Sample No. II. represents the second fall 

 which reached about three or four inches in 

 depth. It is reddish in color. The minerals 

 present are hornblende, indeterminable feld- 

 spars, and biotite. Glass with the refractive 

 index below 1.50 predominates. Some of the 

 glass particles, however, had an index above 

 1.50. Obviously the material in the second 

 fall is more basic than that of the first fall. 



Sample No. III. represents the last faU, is 

 light in color and very finely divided. Inde- 

 terminable feldspars, muscovite, and a few 

 indeterminable particles of what appear to be 

 some ferro-magnesian mineral are present. 

 Glass with index below 1.50 predominates. 

 Apparently the material in the last fall is be- 

 tween the first and second as regards basicity, 

 i. e., chemical composition. 



These three mineralogical analyses indi- 

 cate that the ashes were derived from a 

 mag-ma agreeing fairly well in composition 

 with a granite magma. The silica content of 

 three granites taken more or less at random 

 from Washington" are as follows: (1) 72.48 

 per cent., (2) 76.91 per cent., (3) 74.40 per 

 cent. The refractive index of the glass in 

 these falls at Kodiak shows a silica percentage 

 greater than 72.65, which makes the glass of 

 the samples correspond very nearly in silica 

 content with granite. The silica content of 

 three obsidians, also taken from Washington, 



- For a general description of this eruption see 

 ' ' Volcanoes of Alaska, ' ' The National Geographio 

 Magazine, Vol. XXIII., p. 824, 1912. 



" U. S. Geol. Surv., Professional Paper 14, 1903. 



are as follows: (1) 75.52 per cent., (2) 76.68 

 per cent., (3) 76.20 per cent. These also 

 agree fairly well with the silica content of 

 the glassy part of the ash. 



The analyses also indicate that a partial dif- 

 ferentiation had taken place in the magma. 

 Sample No. II. contains both hornblende and 

 biotite which are not present in sample No. I. 

 Moreover the index of some of the glass par- 

 ticles in No. II. indicates a lower silica con- 

 tent than is the case of the glass of the first 

 and third falls. 



As compared with ordinary soil material 

 these falls are distinguished mainly by the 

 high content of glass. There is every reason 

 to anticipate that these glasses, as well as the 

 definite minerals, would dissolve, hydrolize, 

 and behave as would ordinary soil minerals. 

 In fact the glasses would probably react with 

 the soil water more rapidly than crystalline 

 components of the soil. 



No substances deleterious to plant growth 

 were revealed by the examination, and on the 

 whole these falls will probably serve ultimately 

 as an enrichment of the preexisting soil, al- 

 though it by no means follows that the im- 

 mediate eiiects wiU be satisfactory. 



William H. Ert 



BuEEAU OP Soils, 



U. S. Department op Ageicxjltdee 



SOCIETIES AND ACADEMIES 



THE AMEKICAN MATHEMATICAL SOCIETT 



The one hundred and sixtieth regular meeting 

 of the American Mathematical Society was held 

 at Columbia University on Saturday, October 26, 

 extending through the usual morning and after- 

 noon sessions. Fifty-two members were in attend- 

 ance. Among those present were Professors Emile 

 Borel, of the University of Paris, and Vito Vol- 

 terra, of the University of Rome. 



Vice-president Taber occupied the chair. .The 

 council announced the election of the following 

 persons to membership in the society: Dr. Henry 

 Blumberg, Brooklyn, N. Y.; Mr. J. M. Colaw, 

 Monterey, Va. ; Dr. P. M. Morgan, Dartmouth 

 College; Dr. Louis O 'Shaughnessy, University of 

 Pennsylvania; Dr. C. T. Sullivan, McGill Uni- 

 versity. 



Luncheon was served at the university. In the 



