Januaey 3, 1908] 



SCIENCE 



25 



of books and pamphlets, was consigned to the 

 care of the state librarian, who is to catalogue 

 and shelve the collection, and make it as avail- 

 able for use by the members and the public as 

 is any part of the library. The academy re- 

 serves the right to remove the collection at 

 any time under certain stipulated conditions. 

 A discussion of the general welfare of the 

 academy developed the need of bringing more 

 of the science men into closer touch with the 

 work of the academy, and of extending its in- 

 fluence to every part of the state. For this 

 work a committee was appointed whose duty 

 it is to devise a way of bringing the work of 

 the academy more directly to the attention of 

 the scientists. And as a further means to the 

 same end it was decided to hold the winter 

 meeting's at different educational centers in- 

 stead of at Indianapolis, which for years has 

 been the stated meeting place. Finally, it was 

 the general feeling that interest would in- 

 crease if the state appropriation for publishing 

 the Proceedings could be increased so that the 

 papers would appear in a more extended form 

 and if separates of the papers could be secured 

 at a more reasonable price. The summer 

 meeting was discontinued for the present. 



James H. Ransom, 



Secretary 



THE PHILOSOPHICAL SOCIETY OF WASHINGTON 



The 639th meeting of the society was held 

 November 23, 1907— President Hayford in the 

 chair. Mr. Fred E. Wright spoke of " Recent 

 Improvements in the Petrographic Micro- 

 scope " describing briefly the most important 

 improvements which have been made in the 

 petrographic microscope during recent years. 

 The different attachments and accessories 

 were considered especially with reference to 

 their general applicability and the degree of 

 accuracy attainable by their use. The speaker 

 explained that the improvements had been 

 chiefly brought about by the demands of 

 geologists and mineralogists. The optical 

 priirciples involved in the study of minerals, 

 and how these can be applied in mineral classi- 

 fication, were briefly defined. With the micro- 

 scopes now available it is possible to measure 



the refractive index of mineral grains that 

 are only a few thousandths of a millimeter in 

 diameter. Special mention was made of the 

 double micrometer ocular for determining 

 optic axes of minerals. By its aid the optical 

 angle can be measured to one degree if both 

 axes are visible, or to 3° if only one is visible. 

 Special appliances were also shown for meas- 

 uring the extinction angle by the use of which 

 the best accuracy attainable is from 10' to 15'. 



Mr. W. P. White presented a paper on 

 " Calorimetric Measurements within the Elec- 

 tric Furnace." The special furnace which it 

 was proposed to use in the high temperature 

 measurements, and the conditions which the 

 electric furnace imposes on high temperature 

 problems were briefly mentioned. The diffi- 

 culty of obtaining a good calorimeter was 

 pointed out. 



The method of dropping heated bodies from 

 a furnace into a calorimeter is familiar and 

 satisfactory, but fails to give many inversion 

 — and latent heats which require to be deter- 

 mined on a rising temperature. Dropping 

 into a furnace or manipulation with it is 

 exceedingly difficult. By measuring the heat 

 flowing into a crucible by means of the differ- 

 ence of temperature between crucible and fur- 

 nace wall, a new and simple radiation method 

 is obtained. In a preliminary survey, this 

 method was satisfactorily applied to 2-gram 

 charges of silicates as high as 1560°. The 

 temperature rose 8° a minute; the temperature 

 difference (furnace wall — crucible) was about 

 3°, which was measured to 0.1°. Results 

 agreed within six per cent. By keeping the 

 temperature difference constant and varying 

 the rate, systematic errors in the reading of 

 the thermoelements were avoided. This 

 method compares the latent with the specific 

 heat, which is then to be determined by the 

 dropping method. ^ ^ ^^^^^^ 



Secretary 



the TORREY BOTANICAL CLUB 



The meeting for November 2Y, 1907, was 

 called to order at the Museum Building of the 

 New York Botanical Garden at 3:45 p.m. 

 by the secretary, and Dr. N. L. Britton was 



