July 1, 1904.] 



SCIENCE. 



17 



logued by the Royal Society. This collection 

 has never been published, the manuscript be- 

 ing still in possession of Professor W. W. J. 

 Nicol, the secretary of the committee. For 

 this reason the author undertook the prepara- 

 tion of a bibliography of solubilities only for 

 the years 1875 to 1903, inclusive, and for its 

 compilation carefully examined the tables of 

 contents or indices of twenty-six chemical 

 journals and in addition gives references to 

 papers contained in a great many other jour- 

 nals. Short abstracts enumerating the chem- 

 ical substances employed in the work are given 

 for each reference and at the end an indexed 

 list of all chemical compounds which have 

 been employed in solubility investigations is 

 given. 



At the conclusion of the formal program 

 for the evening- Dr. Wm. H. Seaman, of the 

 Patent Office, exhibited and explained a new 

 form of spirometer (small gasometer) which 

 may be used for testing the lung capacity, 

 analyzing air, measuring gases, etc. 



A Correction. — At the request of Dr. Chas. 

 Baskerville the following correctioif in the 

 report of his lecture contained in the May 13 

 issue of Science, page 758, is made. He did 

 not call ' especial attention to the observation 

 that all minerals which have the property of 

 becoming phosphorescent under the action of 

 radium rays contain the element helium,' hut 

 that ' those minerals which are known to con- 

 tain helium and are radio-active give off a gas 

 or emanation when heated, which may be con- 

 densed by liquid air and exliibits the same 

 properties of causing Sidal's blende to phos- 

 phoresce as do the emanations of radium com- 

 pounds and thorium dioxide.' 



A. Seidell, 

 Secretary. 



THE PHILOSOPHICAL SOCIETY OF WASHINGTON. 



The 587th regular meeting was held on 

 May 21, 1904, "Vice-president Day in the chair. 



A memorial address on the late Major J. 

 W. Powell was read by Dr. W. H. Dall. A 

 sketch of his life was given and some of his 

 achievements; he was said to be far-seeing, 

 much in advance of his time, as on Indian 

 questions and irrigation; his predominant 



characteristics were courage, sympathy and 

 insight. 



Professor E. A. Pace, of the Catholic Uni- 

 versity, then spoke by invitation on ' The 

 Rhythm in Visual Perception.' In the at- 

 tempt to distinguish between physiological 

 and (possible) physical phenomena the study 

 of threshold phenomena may throw much 

 light. So the fluctuations in the perception 

 of a constant,^ just visible light have been 

 studied. Various writers have attributed 

 them to the afferent nerve, to the central 

 organ, and to fatigue of the ciliary muscle. 

 The speaker had disproved this last view in 

 1891 by the use of atropine. Later observers 

 found the periodicity stands in close relation 

 to vaso-motor activity and respiration. The 

 speaker's recent observations, still incomplete, 

 on after-images show that the fluctuations are 

 due to retinal fatigue. The paper was dis- 

 cussed by the audience with reference to its 

 bearings on observations on variable stars, 

 and on the velocity of light by the Pizeau- 

 Cornu method. 



Mr. J. P. Hayford, of the Coast and 

 Geodetic Survey, reported on ' A Test of the 

 Transit Micrometer, as a Means of Elimin- 

 ating Personal Equation.' In this instru- 

 ment the observer attempts to keep the wire 

 on the star, and the instants when the wire 

 passes certain flxed positions are electrically 

 recorded on the chronograph sheet. The prac- 

 tical result is that in difi^erence-of-longitude 

 work three nights' observations by the new 

 method without change of observers are equal 

 to ten nights with exchange by the old key 

 method. 



After some discussion the society adjourned 

 till October 15. 



Charles K. Wead, 



Secretary. 



THE NEW YORK ACADEMY OF SCIENCES. 

 SECTION OF ASTRONOMY, PHYSICS AND CHEMISTRY. 



The regular meeting of the section was 

 held on May 2 at the American Museum of 

 Natural History. The program consisted of 

 four papers, abstracts of which are as follows : 

 The Theory of a Double Suspension Pendu- 

 lum: E. S. Woodward. 



