PROCEEDINGS OF THE ACADEMY AND AFFILIATED 



SOCIETIES 



WASHINGTON ACADEMY OF SCIENCES 



At the 66th meeting, at the Cosmos Club, January 5, 1911, Dr. John 

 A. Brashear delivered an address on The contributions of photography 

 to stellar research. 



The author discussed in a clear and charming manner many of the 

 contributions that photography has made to our knowledge of astronomy 

 and illustrated each with beautiful pictures. 



The 67th meeting, at the Cosmos Club, 4:40 p.m., January 19, 1911, 

 was for the transaction of routine business and the election of officers 

 for the ensuing year, as follows: President, F. W. Clarke; Non-resident 

 Vice Presidents, T. C. Chamberlin, H. F. Osborn; Corresponding Secre- 

 tary, Frank Baker; Recording Secretary, W. J. Humphreys; Treasurer, 

 A. L. Day; Resident Vice Presidents, nominated by the affiliated socie- 

 ties; Anthropological Society, Walter Hough; Archaeological, Mitchell 

 Carroll; Biological, David White; Botanical, W. E. S^fford; Cherrical, 

 H. W. Wiley; Engineers, M. 0. Leighton; Entomological, A. D. Hop- 

 kins; Foresters, Gifford Pinchot; Geographic, Henry Gannett; Geolog- 

 ical, A. H. Brooks; Medical, W. M. Barton; Historical, J. D. Morgan; 

 Philosophical, Lyman J. Briggs. 



At the 68th meeting, at the Cosmos Club, January 19, 1911, Dr.F. 

 M. Jaeger, Professor of Chemistry in the University of Groningen, 

 Holland, spoke On doubly-refracting liquids and the so-called liquid crys- 

 tals. 



The subject of "liquid crystals" and "anisotropic liquids" is one of 

 experimental research and also of theoretical speculation, and has a 

 most important significance for both chemistry and physics, since it is 

 fundamental to our theoretical ideas on the real nature of liquids. 



When we ask ourselves how far it is right to speak of "liquid crystals, 

 we can treat the question from two sides: First, as to how far liquids can 

 exhibit properties that have seemed to be typical- of "crystalline" mat- 

 ter; and second, to what degree crystals can share the characteristics 

 of a "liquid" in the common sense of the word. 



The typical property of crystalline matter is its anisotropy, or the 

 rigorous dependence of the physical properties cf crystals on the special 

 direction in which those properties are observed. In most cases such 

 media are optically anisotropic, a condition that insures the easiest and 

 most certain detection and measurement of this property. 



It is well known that true liquids can become birefringent under th e 



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