ABSTRACTS 



Authors of scientific papers are requested to see that abstracts, preferably 

 prepared and signed by themselves, are forwarded promptly to the editors. 

 Each of the scientific bureaus in Washington has a representative authorized to 

 forward such material to this journal and abstracts of official publications should 

 be transmitted through the representative of the bureau in which they originate". 

 The abstracts should conform in length and general style to those appearing in 

 this issue. 



SPECTROSCOPY. — Wave-lengths of the stronger lines in the helium 

 spectrum. Paul W. Merrill. Bureau of Standards Scientific 

 Paper No. 302 (Bull. Bur. Stds., 14: 159-166). 1917. 

 Wave-lengths of twenty-one of the stronger helium lines have been 

 carefully measured photographically by means of the Fabry and Perot 

 type of interferometer, using several separations. Nine of the lines 

 were compared directly with the standard cadmium line 6438.4696A, 

 the remaining lines being referred to these. The accuracy attained 

 is nearly 0.001 A, so that the lines are now available as convenient 

 standards for many purposes. It is well known that the separation 

 of the effective reflecting surfaces of the interferometer usually appears 

 to be slightly different for different colors ; the possibility of eliminating 

 this effect is noted. The Kayser and Runge spectral series formula 

 with constants derived from three consecutive lines will not reproduce 

 accurately even the next member of any one of the six series. 



P. W. M. 



MINERALOGY. — An American occurrence of miloschite. Edgar T. 



Wherry and Glenn V. Brown. American Mineralogist, 1: 



63-67. 1916. 



The discovery of this mineral at Ely, Nevada, is announced, and a 



full description of its properties and composition given. It is shown to 



be a chromium-bearing kaolinite, and is considered a mineral species. 



E. T. W. 



PALEOBOTANY. — Two new fossil plants from the Triassic of Pennsyl- 

 vania. Edgar T. Wherry. Proc. U. S. Nat. Mus., 51: 327-329. 

 1916. 

 Descriptions of a new conifer, Palissya longifolia, and of a plant of 

 unknown relationships, named Brunswickia dubia, from the Brunswick 

 formation, in which it occurs. E. T. W. 



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