June 11, 1909] 



SCIENCE 



949 



strengthened when two or more of the relation- 

 ships outlined above exist. 



The general conclusion reached may be stated 

 as follows: Both igneous and sedimentary rocks 

 undergo chemical changes during dynamic meta- 

 morphism. Such changes in the sedimentary rocks 

 are of considerable magnitude and their character 

 is fairly well known. In the igneous rocks changes 

 during dynamic metamorphism appear to be of 

 much lesser magnitude and their character is not 

 so well understood. The lesser degree of chemical 

 alteration that they undergo as compared with the 

 sediments makes it possible to distinguish between 

 the two in many instances on chemical grounds. 

 Copper-hearing Amygdaloids of the White River 



Region, Alaska: Adouh Knopf. 



The copper-bearing rocks of the White River 

 region, Alaska, comprise a stratiform succession 

 of basaltic amygdaloids, porphyritic sheets, tuffs 

 and breccias, several thousand feet thick, and 

 constitute the dominant portion of a formation 

 of Carboniferous age. In places the amygdaloids 

 are highly zeolitie, and the zeolites form from 

 25 to 50 per cent, of the bulk of the rock. Native 

 copper has been found intergrown with prehnite, 

 calcite and zeolites filling the vacuoles in the 

 ancient lavas. At some localities veinlets of 

 chalcocite and laumontite cut the volcanics; at 

 others there occur drusy veinlets consisting of 

 quartz, chalcocite and a black combustible min- 

 eral, which when ignited burns with a smoky 

 yellow flame. Veinlets of spherulitic prehnite 

 intergrown with calcite and flecked with native 

 copper and chalcocite, also traverse the amygda- 

 loids. The association of a carbon mineral with 

 cupriferous zeolitie amygdaloids appears to be a 

 novel feature, and it is believed to afford a satis- 

 factory explanation for the precipitation of the 

 metallic copper from the mineral-bearing solutions. 

 Feancois E. Matthes, 



THE PHILOSOPHICAL SOCIETY OF WASHINGTON 



The 665th meeting was held in the afternoon 

 of April 26, Vice-president Day in the chair. 



At this meeting, which was complimentary to 

 the American Physical Society, Professor Dr. Max 

 Planck, of Berlin, addressed the society, by invi- 

 tation, his subject being " Die Mechanik als 

 Grundlage der Physik." 



The Star List of the American Ephemeris: Mil- 

 ton Updegkafp, U. 8. Naval Observatory. 

 Professor Updegraff gave an account of the star 

 list of the " American Ephemeris " as contained 

 in the first volume of that publication, which is 

 for the year 1855, and also of the star lists con- 

 tained in the five other national ephemerides of 

 that date. He gave in detail the features of the 

 star list of the " American Ephemeris " and 

 " Nautical Almanac " as it will appear in the 

 volume for the year 1912. The number of stars 

 is to be 825: 800 ten-day stars, 15 northern cir- 

 cumpolar stars and 10 southern circumpolar 

 stars; all eircumpolars having their apparent 

 places given for every day in the year. Provision 

 will be made for convenient computation of the 

 effect of the short terms of the nutation for each 

 of the ephemerides of the ten-day stars. These 

 short terms at their maxima and minima have an 

 effect in declination of about a tenth of a second 

 of arc, and in right ascension of nearly a hun- 

 dredth of a second of time multiplied by the 

 tangent of the declination, and are sufiiciently 

 large to make it necessary to take them into 

 account in the more accurate kinds of astronom- 

 ical work. 



Attention was called to the fact that in the 

 " American Ephemeris " the short terms have 

 been included in the Besselian and independent 

 star numbers since the volume for the year 1882, 

 and this fact makes it desirable that the effect 

 of these terms should also be allowed for in the 

 ten-day ephemerides of the stars, although they 

 can not be included directly, as the variation is 

 so rapid as to render interpolation impossible. 



A brief account was also given of the star lists 

 contained in the issues for 1910 of the four other 

 national ephemerides. Attention was called to 

 the fact that in the new star list of the " Amer- 

 ican Ephemeris " the constants adopted by the 

 Paris Conference of the directors of national 

 ephemerides, held in 1896, have been used instead 

 of the Struve-Peters constants which have hitherto 

 been used in the " American Ephemeris," except- 

 ing the volume for the year 1900, in which the 

 conference constants were used. 



An account was also given of Professor New- 

 comb's suggested list of fundamental stars, which 

 is now used as the basis of the star lists of all the 

 national ephemerides excepting the Berliner Jahr- 



The 666th meeting was held on May 8, 1909, 

 Past-president Marvin in the chair. Two papers 

 were read. 



The Solar Parallax froin Ohservations on the 

 Planet Eros: C. W. Fbedeeick, U. S. Naval 

 Observatory. 



