920 



SCIENGE. 



[N. S. Vol. VIII. No. 208. 



By successive applications of the formula, 

 curves were constructed for negative amphi- 

 boles on rectangular coordinates, in which the 

 ordinate indicates the value of the extinction- 

 angle on (010), and the abscissa the amount of 

 rotation of the 'plan mobile,' out of the plane 

 of symmetry toward the orthopinacoid. These 

 curves were plotted for amphiboles in which 

 the optical angle is 50°, 60°, 70°, 80°, and the 

 extinction-angle on (010), in each case, 10°, 15° 

 or 20°. To these were added the analogous 

 curves for 2V=90°. The last were unlike the 

 former in that they showed no maximum value 

 of extinction between (010) and (100). When 

 the optical angle is small, the maximum ex- 

 tinction may be found to be in a plane far re- 

 moved from (010), contrary to the statement of 

 Zirkel that the maximum must always lie in 

 the plane of symmetry. 



Secondly, a method for determining the ex- 

 tinction-angle of amphiboles and pyroxenes 

 (010) was proposed. The object of this new 

 method is to avoid cutting oriented sections, as 

 this operation is manifestly impossible with 

 many rock- forming varieties. 



' Two Remarkable Explosions in the New 

 York Oil District ' were described by Mr. L. 

 LaForge. On March 1, 1898, three hundred 

 quarts of nitro-glycerine exploded in a maga- 

 zine, about one mile east of Wellsville, N. Y. 

 Structures in that village suffered much damage; 

 chimney-tops fell and windows were broken 

 inward. One week later, six hundred quarts 

 of nitro-glycerine exploded in the new maga- 

 zine on the same spot. In this case no serious 

 damage to buildings in the village resulted, al- 

 though the report and shock of the explosion 

 extended much farther. When the former ex- 

 plosion took place the ground was frozen, but 

 before the latter occurred it had thawed out. 

 It is to this fact that the people of Wellsville 

 attribute the difference between the results of 

 the two explosions. 



J. M. BOUTWELL, 



Becording Secretary. 

 THE ACADEMY OF SCIENCE OF ST. LOtTIS. 



At the meeting of the Academy of Science 

 of St. Louis on the evening of December 5, 

 1898, Mr. H. von Schrenk presented by title a 



paper ' On the Mode of Dissemination of Usnea 

 harbata,' and Professor L. H. Pammel pre- 

 sented by title a paper on ' The Histology of 

 the Caryopsis and Endosperm of some Grasses.' 

 Dr. Theo. Kodis presented the results of some 

 experiments on overcooling animal and vege- 

 table tissues, in which it was shown that, as 

 water may, under favorable conditions, be 

 cooled to some distance below zero, Centigrade, 

 without freezing — the temperature immediately 

 rising to the freezing point the moment that 

 freezing begins, and remaining there until the 

 water is entirely solidified, then beginning once 

 more to drop — so, when animal and vegetable 

 tissues are experimented on, they may be cooled 

 to a temperature decidedly lower than the freez- 

 ing point, under favorable conditions, before 

 freezing begins, but that, when it begins, the 

 temperature at once rises to the freezing point 

 (which is always somewhat lower than that of 

 pure water), remaining there until the process of 

 freezing is complete, when it once more begins 

 to fall. The speaker gave a short account of 

 the current theories as to the mechanical con- 

 stitution of protoplasm, and discussed the bear- 

 ing on them of the phenomena when the solidi- 

 fication of overcooled tissues began. 



William Trelease, 

 Recording Secretary. 



NEW BOOKS. 



Apergus de taxonomie generate. J. P. Dueand. 

 Paris, Felix Alcan. 1899. Pp. 265. 5 fr. 



Natalite et Democratic. Aesene Dumont. Paris, 

 Schleicher Freres. 1898. Pp. 230. 



Catalogus Mammaleum tarn viventium quam fossil- 

 ium. E. L. Teoussaet. Berlin, R. Fried- 

 lander und Sohn. 1898. Fasciculus IV. and 

 V. Pp. 665-1264. 26 Marks. 



Principles of Biology. Heebert Spencee. 

 New York, D. Appleton & Co. 1898. Re- 

 vised and Enlarged Edition. Vol. I. Pp. 

 X + 706. $2.00. 



Degeneracy. Eugene S. Talbot. London, 

 Walter Scott, Ltd. ; New York, Charles 

 Scribner's Sous. 1898. Pp. xvi + 37. SI. 50 



Psychologie der Veriinderungsauffassung. L. 

 William Steen. Breslau, Preuss und Yiin- 

 ger. 1898. Pp. viii + 264. 



