April 7, 1911] 



SCIENCE 



549 



the jar along with the cultures of the abortion 

 bacillus. The appearance of the colonies is char- 

 acteristic, and coupled with the behavior toward 

 oxygen is almost sufficient for identification. 

 Subcutaneous injection of active cultures into 

 pregnant guinea-pigs causes abortion with great 

 regularity. 



Of the various names employed to designate the 

 organism, Bacillus (or Bacterium) abortus Bang, 

 is considered as the correct and appropriate one. 

 A Method for Determining the Germicidal Value 



and Penetrating Power of Liquid Disinfectants : 



Arthur I. Kendall and Martin E. Edwards. 



The method consists essentially of infecting 

 plain agar with 24-hour cultures of B. coli, hard- 

 ening the agar in sterile tubes of 1.5 cm. inside 

 diameter and about 1 meter long, then cutting 

 cylinders from the hardened agar by running it 

 out slowly and sectioning it transversely into cylin- 

 ders of about 2 cm. long with a sterile knife. The 

 cylinders so obtained are dropped directly into the 

 disinfecting solutions which it is desired to ex- 

 amine, and into 5 per cent, carbolic acid as a 

 standard for comparison. Cylinders from each 

 solution of disinfectant are removed at the end of 

 stated intervals, washed in distilled, sterile water, 

 and then a core removed from the center of each 

 cylinder along the long axis by means of sterile 

 quill tubing (3 mm. in diameter). 



These cores so removed are placed in lactose 

 fermentation tubes and incubated at body tem- 

 perature for several days, making daily examina- 

 tions for gas formation. 



By comparing the results obtained with the 

 various disinfectants with those of the standard 

 carbolic acid, it is possible to formulate a coeffi- 

 cient which expresses the combined germicidal and 

 penetrating power of the disinfectant in question 

 with that of carbolic acid. 



All abstracts have been supplied by authors un- 

 less otherwise stated. 



Charles E. Marshall, 



Secretary 



East Lansing, Mich. 



SOCIETIES AND ACADEMIES 

 the philosophical society or Washington 

 The 690th meeting was held on February 25, 



1911, President Day in the chair. Two papers 



were read: 



Some Causes of Variations in the Polarization of 

 Sicy Light: Dr. H. H. Kimball, of the V. S. 

 Weather Bureau. 



The first part of this paper contained a brief 

 resume of the main features of sky polarization, 

 together with references to some of the theories 

 that have been advanced to account for them. 

 Observations by different investigators were cited 

 to illustrate the character of periodic variations in 

 sky polarization, and a summary was given of 

 observations by the author. These latter include 

 measurements of the percentage of polarization at 

 the point of maximum, i. e., 90 degrees from the 

 sun and in its vertical, as well as observations on 

 the position of the neutral points of Arago and 

 Babinet. They show (1) variations in sky polar- 

 ization with place, apparently due principaBy to 

 differences in the intensity of reflection from the 

 surface of the earth, and (2) variations with 

 meteorological conditions. 



No connection is apparent between sky polariza- 

 tion and the pressure exerted by the aqueous 

 vapor contained in the atmosphere. Dustiness, or 

 any form of mechanical haze, decreases the per- 

 centage of polarization ; but by far the most 

 potent cause of svich a decrease appears to be 

 optical haze, or the diffusion of light by reflection 

 from the boundary surfaces of non-homogeneous 

 layers or currents of air. 



All of the observations included in the above 

 summary were obtained when the sky was prac- 

 tically cloudless. Of the ten days on which the 

 lowest percentage of polarization was observed 

 seven were followed by rain before midnight of 

 the succeeding day. 

 The Nature of the Sun: Dr. C. G. Abbot, of the 



Smithsonian Institution. 



In the preparation of a forthcoming book on 

 the sun the speaker had attempted to explain solar 

 phenomena on the hypothesis that the sun is com- 

 pletely gaseous, and not possessing the shell of 

 clouds generally assumed to constitute the photo- 

 sphere. The temperature of the sun seems to be 

 of the order of 6500° absolute centigrade, and the 

 pressure in the iron reversing layer about five 

 atmospheres. In these circumstances it seems 

 highly improbable that matter other than gaseous 

 exists. A continuous spectrum was held by the 

 speaker to be the natural consequence of the im- 

 mense thickness and considerable pressure of the 

 radiating gas sphere. A sharp boimdary exists 

 because the molecular scattering of light prevents 

 the view at the center of the sun's disc from pene- 

 trating more than perhaps one thousand kilo- 

 meters. A view at the sun 's edge will be oblique, 

 and to furnish gas one thousand kilometers thick 



