898 



SCIENCE 



[N. S. Vol. XLIII. No. 1121 



Schlatter's disease. An importaut feature is 

 the large number of new words with which the 

 medical vocabulary has been enriched during 

 the last few years. The book contains such 

 new words as anoei-association, biometer, eolli- 

 culectomy, gassed, keritherapy, leukotoxic, 

 serobacterins, sympathoblasts, etc. 



This handy, practical book, in octavo size, 

 1^ inches thick, containing nearly 71,000 

 words, is unique among modern dictionaries 

 and can not fail to receive a hearty welcome by 

 the medical practitioner and the student of 

 medicine. 



A. Alleman 



Aemt Medical Museum 



PROCEEDINGS OF THE NATIONAL 

 ACADEMY OF SCIENCES 



(Volume 2, Number 5) 

 The fifth nimiber of Volume 2 of the Pro- 

 ceedings of the National Academy of Sciences 

 contains the following articles: 



1. The High Frequency Spectrum of Tung- 

 sten: Albert W. Hull and Marion Eice, 

 Research Laboratory, General Electric Com- 

 pany. 



The authors show two photographs of the 

 spectrum of X-rays taken in the usual man- 

 ner in a rock-salt crystal. They also give fig- 

 ures which show the ionization current as a 

 function of the angle of incidence. A com- 

 parison with previous results obtained by 

 others is sketched. 



2. On the Foundations of Plane Analysis 

 Situs: Robert L. Moore, Department of 

 Mathematics, University of Pennsylvania. 

 As point, limit-point and regions (of certain 



types) are fundamental in analysis situs, the 

 author has set up two systems of postulates for 

 plane analysis situs based upon these notions; 

 each set is sufficient for considerable body of 

 theorems. 



3. A General Theory of Surfaces: Edwin B. 

 Wilson and C. L. E. Moore, Department of 

 Mathematics, Massachusetts Institute of 

 Technology. 



Continuing the work of Kommerell, Levi 

 and Segre, a theory of two-dimensional sur- 

 faces in n-dimensional space is developed by 



the method of analysis outlined by Ricci in 

 his absolute differential calculus. 



4. Dynamical Stahility of Aeroplanes : Jerome 

 C. HuNSAKER, U. S. Navy and Massachusetts 

 Institute of Technology. 



A comparative detailed study of two aero- 

 planes, one a standard military tractor, the 

 other designed for inherent stability, is made 

 for the purpose of reaching general conclusions 

 of a practical nature with respect to aeroplane 

 design. It appears that inherent stability 

 (except at low speed) can be obtained by care- 

 ful design without departing seriously from 

 the standard type now in use. 



5. cuffed Islands in the Coral Seas: W. M. 

 Davis, Department of Geology and Geog- 

 raphy, Harvard University. 



The author extends his former work on the 

 Origin of Coral Reefs to include the explana- 

 tion of the cliiis of exceptional reef-encircled 

 islands of which no adequate explanation has 

 previously been given. 



6. On Some Relations hetween the Proper Mo- 

 tions, Radial Velocities and Magnitudes of 

 Stars of Classes B and A : C. D. Perrine, 

 Observatorio Nacioual Argentino, Cordoba. 

 The velocity distribution of classes B-B5 



and A differ from the distributions found for 

 the F, G, K and M classes by Kapteyn and 

 Adams. 



7. Asymmetry in the Proper Motions and 

 Radial Velocities of Stars of Class B and 

 Their Possible Relation to a Motion of Ro- 

 tation : C. D. Perrine, Observatorio Nacional 

 Argentino, Cordoba. 



Stars of class B show differences in the 

 proper motions in the two regions of the 

 Milky Way at right angles to the direction of 

 solar motion; the differences appear to be best 

 explained by a general motion of rotation of 

 the system of stars in a retrograde direction 

 about an axis perpendicular to the Milky Way. 



8. Theory of an Aeroplane Encountering 

 Gusts: Edwin Bidwell Wilson, Department 

 of Mathematics, Massachusetts Institute of 

 Technology. 



The longitudinal motion of an aeroplane en- 

 countering head-on, vertical, or rotary gusts is 

 discussed by the method of small oscillations. 



