602 



SCIENCE. 



[N. S. Vol. XVIII. No. 402. 



chosen for the comparisons of brightness, and 

 the stars already known to be variable, all the 

 positions being given in seconds of arc, and 

 determined from the center of the particular 

 cluster. In Plates VIII. to XII. are given 

 reproductions from the original plates of 

 fourteen clusters, on which the variables and 

 comparison stars are marked. On these re- 

 productions 1 mm. equals about 10". Es- 

 pecially interesting are the repeated enlarge- 

 ments of certain portions of some clusters, 

 which are given in the last plate of the vol- 

 ume. These show clearly the change in ap- 

 pearance of the variables on different plates, 

 and give an idea of the certainty with which 

 the comparison with adjacent stars can be 

 made. 



From the materials given in the appendix 

 one sees that there still remains a very great 

 amount of labor to be done. We hope that 

 the author will be able to carry out his plan, 

 and to give as clear and exhaustive a dis- 

 cussion of the light changes in the~ other star 

 clusters, as he has done in the present volume.* 



G. MiJLLER. 



SCIEXTIFIG JOURNALS AND ARTICLES. 



The contents of the American Journal of 

 Science for November are as follows : ' Min- 

 eralogical Notes,' by C. H. Warren ; ' Studies 

 of Eocene Mammalia in the Marsh Collection, 

 Peabody Museum ' (with plates XVI. and 

 XVII.), by J. L. Wortman; ' Tridenum Vir- 

 ginicum (L.) Eafin,' a morphological and an- 

 atomical study (with figures in the text), by 

 T. Holm ; ' Ephemeral Lakes in Arid Eegions,' 

 by 0. R. Keyes ; ' Note on the Identity of 

 Palacheite and Botryogen,' by A. S. Eakle; 

 ' Colloidal Gold : Absorption Phenomena and 

 Allotropy,' by J. C. Blake. 



SOCIETIES AND ACADEMIES. 



AMERICAN CHEMICAL SOCIETY. NEW YORK 

 SECTION. 



The first meeting of the season was held at 

 the Chemists' Club, No. 108 West 55th Street, 

 on Friday evening, October 9. 



* Translated from Vierteljahrsschrift der 

 Astron. Gesellschaft, 38. Jahrgang, Erstes Heft, 

 1903. 



After a few remarks by the chairman, Pro- 

 fessor Miller, outlining the policy of the section 

 for the ensuing year, and requesting members 

 to present papers in abstract as far as possible, 

 so as to have more time for discussion, the 

 following papers were read : 

 The Volumetric Determination of Zinc: W. J. 

 Waring. 



This paper was read by Mr. Stone and dis- 

 cussed by Messrs. Brenneman, Stone, Miller 

 and Danziger. It called attention to the 

 widely differing results which are obtained by 

 different chemists in the determination of 

 zinc by the ferrocyanide titration method, and 

 pointed out the necessity of uniformity in the 

 conditions of standardizing and titrating, so 

 that the composition of the precipitate shall be 

 uniform. The occurrence of cadmium in the 

 ores of the Joplin District in amounts varying 

 from 0.1 to 2 per cent, was shown to interfere 

 with the accuracy of the method, so that the 

 cadmium should be removed, best by aluminum 

 foil, before the titration. A new cadmium 

 ammonium ferrocyanide was also described. 

 The Reduction of Lead from Litharge in Pre- 

 liminary Assays and the Advantages of an 

 Oxide Slag: E. H. Miller, E. J. Hall and 

 M. J. Falk. 



Professor Miller gave an abstract of an 

 article which will soon appear in the Transac- 

 tions of the American Institute of Mining 

 Engineers. It was shown in making pre- 

 liminary assays to determine the reducing 

 power of an ore that, not only did the amount 

 of lead reduced vary with the acid or basic 

 character of the slag, but that the amount of 

 lead oxidized by niter varied with the reducing 

 agent present, even under uniform conditions 

 as to charge, time and temperature. This was 

 not anticipated, and explains the difficulty in 

 the old preliminary assays. 



The best results were obtained by using a 

 charge of ore 3 grams, litharge 50 grams, soda 

 10 grams, no silica, no borax glass and no 

 salt cover. With this charge and a tempera- 

 ture of over 900° C. the sulphur is completely 

 oxidized to sulphate and forms an upper layer 

 in the slag (Na.CO, and Na,SO,), while the 

 lower layer consists of a readily fusible mix- 

 ture of oxide of lead, of iron, etc. 



