350 



SCIENCE. 



[N. S. Vol. XI. No. 270. 



escape from the conclusion that the birds were 

 subject to a musical evolution that paralleled 

 our own. 



Mr. M. G. Kains presented a paper upon ' The 

 Eifects of the Electric Arc Light iu the Culture 

 of Easter Lilies,' giving the results of experi- 

 ments conducted during the winter of 1895, at 

 Cornell University, under the direction of Pro. 

 fessor L. H. Bailey. Three divisions of the 

 plants were made, one in the full glare of the 

 naked light, one iu which the light first passed 

 through a pane of glass, and one where no 

 light was employed. The light burned nightly 

 for four months and uniform cultural conditions 

 were maintained throughout the tests. Plants 

 in the light sections were taller, blossomed 

 earlier, were less robust and their flowers 

 shorter lived than those grown in the dark, 

 blossoms in the naked light exhibited a dark 

 brown burn upon the surface facing the lamp, 

 and blossoms upon plants grown in the dark 

 lasted two days longer than those in the light. 

 From the experiments it is concluded that com- 

 mercial use might be made of the arc light after 

 the lily buds are an inch long, and that the 

 light must pass through a glass to screen out 

 the ultra-violet rays of the spectrum. 



E. V. Wilcox discussed ' Lupines as Plants 

 Poisonous to Stock,' saying that cattle and 

 sheep varied greatly in their liking for the grow- 

 ing plants, some animals eating them with 

 avidity and others caring little for them. The 

 poisonous properties of the Lupines appeared 

 to reside in the seeds or seed pods, for, while the 

 plants were usually eaten with impunity, great 

 mortality had been known to occur among stock 

 which was forced by a fall of wet snow to feed 

 on plants from which the leaves had mostly 

 fallen while the seed pods remained. On the 

 large ranges of the west, where forage plants 

 were not cultivated, Lupines were frequently so 

 abundant that they were cut and dried like hay 

 for use in winter, and the speaker noted a case 

 where sheep fed on this Lupine hay were seem- 

 ingly driven mad. T. W. Stanton, 



Secretary. 



THE PHILOSOPHICAL SOCIETY OF WASHINGTON. 



The 512th meeting of the Society was held 

 on February 3, 1900, at the Cosmos Club. 



After a general discussion on the method of 

 publication of the Bulletin^ the first regular 

 paper of the evening was read by Mr. J. G. 

 Hagen, on ' Recent Progress in Astro-physics.' 



During the course of the address the follow- 

 ing three points were discussed : The cluster 

 type of variable stars, the spectroscopic binaries, 

 and the Potsdam photometric catalogue. 



Regarding the first point, the cluster Messier 

 No. 5 was mentioned as presenting a remark- 

 able uniformity in its variable stars. Out of 

 900, visible on the plates obtained in Arequipa 

 with the 13-inch Boyden refractor, 63 were recog- 

 nized as variables, and 40 of them were meas- 

 ured accurately from nearly a hundred plates. 

 The mean period of all except two is about 

 12 J hours, with a mean range of 1.1 magnitude. 

 It was suggested that, with Pogson's light factor 

 0.4, the common range of 1.1 magnitude could 

 be explained by supposing each variable to be a 

 binary system, with components of equal bright- 

 ness. The cluster would then consist of many 

 binary systems, each with its orbital plane pass- 

 ing through the sun, and with a period of revo- 

 lution equal to 25 hours. 



With respect to spectroscopic binaries, Camp- 

 bell's discovery of Polaris as a double system 

 was mentioned. The center of gravity ap- 

 proaches our sun with a velocity of 12 kilo- 

 meters, while Polaris oscillates around it in a 

 period of about four days. The fact that three 

 years previous the mean velocity was found 

 eight kilometers larger, might point to a dis- 

 turbing body. Yet, to pronounce Polaris a 

 triple system, would be premature. Another 

 interesting discovery of a periodic change in 

 the spectrum was recently made by Mrs. Flem- 

 ing in the case of Zeta Centauri, with intervals 

 of two and six days, thus making a period of 

 eight days. The intervals of two and six days 

 were graphically illustrated by an eccentric 

 orbit. Attention was also called to experiments 

 made by Humphrey, Mohler and Wilsing, to the 

 effect that changes in the normal spectrum may 

 be produced bj' changes of pressure in the source 

 of light. 



The third point consisted in a summary of a 

 review of the Potsdam photometric catalogue, 

 recently published in the Vierteljahrsschrift, 

 XXXIV., pp. 288-297. 



