102 RECORDS 



be counted which are ready to break away from the main mass of 

 the dike. Mention was also made, in discussing the glacial geol- 

 ogy of the region, of sand plains and of two well-developed eskers. 



The paper was discussed by Professor Kemp and Doctors 

 Julien and White. 



Doctor Julien exhibited a specimen of fulgurite formed from 

 sand in Poland, with a series of photo- micrographs which he 

 had made from the same. Some new features in fulgurites were 

 pointed out in this specimen ; pustules of glass on the inner 

 lumen, glass fibres on the exterior and adhering sand-grains, 

 two-thirds of which consisted of orthoclase. In the thin cross 

 section, examination of the minute gas cavities showed the ab- 

 sence of condensed water-vapor, and this indicated a dilatation 

 of both lumen and cavities by air, more than by steam. The 

 radial arrangement of layer cavities, the horn-like projections on 

 the outside of the tube, and the pustules along the lumen, were 

 all shown to be connected with relief of intense pressure out- 

 wardly during the electric discharge, or inwardly, during the 

 reaction after its passage. This fulgurite is of further interest 

 in presenting the first instance yet observed of devitrification, 

 the glass being generally filled with delicate crystallites, appar- 

 ently of feldspar. All the bubbles, however, are enclosed in 

 pellicles of homogeneous glass, and some of the larger within 

 a coating of suddenly chilled glass, which is free from crystal- 

 lites. The relation of these facts was discussed in reference to 

 Lagorio's view as to the difficult saturation of a magma by the 

 constituents of feldspar. 



Other occurrences of fulgurites were discussed by Doctors 

 Kemp, Levison and White. 



Theodore G. White, 



Secretary. 



ANNUAL MEETING. 



February 25, 1901. 



Academy met for the Annual Meeting at 8:15, President 

 Woodward in the chair. 



Reports of the officers for the past year were called for and 

 presented in the following order : 



