654 



SCIENCE. 



[N. S. Vol. IX. No. 227. 



Mr. W, C. Kretz read a paper on the ' Posi- 

 tions and Proper Motions of Stars iu Coma 

 Berenices from Rutherfurd Photographs.' 

 Kutherfurd tools fourteen photographs in the 

 years 1870, 1875 and 1876 of the cluster in Coma 

 Berenices. The positions of these stars on the 

 plates were measured with a Repsold measur- 

 ing machine, and the reduction was made by 

 the method worked out by Professor Jacoby. 

 Great precautions were taken to eliminate all 

 possible errors. The positions obtained were 

 compared with those obtained by Chase with 

 the Yale heliometer in 1892. In this manner a 

 catalogue of the positions and proper motions 

 of twenty-four stars was obtained, which was 

 the object of the research. 



Wm. S. Day, 



Secretary. 



THE NEW YORK SECTION OF THE AMERICAN 

 CHEMICAL SOCIETY. 



The regular monthly meeting of the New 

 York Section of the American Chemical Society 

 was held at the Chemists' Club, 108 West Fifty- 

 fifth street on Friday evening, April the 7th ; 

 Dr. Wm. McMurtrie presiding, and about sixty- 

 five members present. 



The following papers were read : ' The Toxic 

 Action of Sodium Fluoride,' by H. B. Baldwin. 

 ' The Chemistry of the By-Products of Coke 

 Ovens,' J. D. Pennock. ' Notes on the Chemis- 

 try of the Carbides,' J. A. Matthews. ' The 

 Distribution of Alkali in Montana,' F. W. 

 Traphagen and W. M. Cobleigh ; read by Mr. 

 Cobleigh. 



Mr. Baldwin said that, owing to the now 

 somewhat extended use of sodium fluoride in 

 the arts and as a preservative and insecticide, 

 there is considerable liability of accidental poi- 

 soning from the substance. Several cases are 

 cited with the symptoms observed, the most 

 prominent of which are nausea and vomiting 

 within a few minutes. One case resulted fatally 

 from an unknown dose, probably about ten 

 grams. Five grams produced serious results in 

 another case. The author took several experi- 

 mental doses and was made ill by 0.25 gram. 

 A case is also cited where about 50 grams were 

 taken with complete recovery. The literature 

 of the substance as a toxic agent is very meagre, 



but experiments have been made by several 

 German and French investigators. Shultz 

 found that by subcutaneous injection the lethal 

 dose per kilogram of body weight was for rab- 

 bits 0.2-0.4 gram, for dogs 0.3 gram and for 

 frogs 0. 005-0. 006 gram. Sodium fluoride should 

 be classed among the less violent poisons and 

 ought to find a place in works on toxicology. 



The paper of Messrs. Traphagen and Cob- 

 leigh was an interesting description of the dis- 

 tribution of alkali in Montana with analytical 

 data. 



Professor Matthews gave a classification of 

 the carbides thus far known, according to their 

 methods of preparation and properties, and de- 

 scribed their commercial development, beginning 

 with carborundum, of which in 1895 the pro- 

 duction was about 300 pounds per diem. Last 

 July the daily output was 4,300 pounds and 

 over. It is said to be harder than emery and 

 lighter. It has been successfully used in plate- 

 glass grinding, as well as for all ordinary pur- 

 poses. Recently it has been put to an entirely 

 new use, that of furnishing silicon to steel, be- 

 ing a substitute for ferro-silicon where the ad- 

 dition of some carbon is not objectionable. 



The calcium carbide industry was also re- 

 viewed, and several uses other than for prepara- 

 tion of acetylene were mentioned, as follows : 

 Drying alcohol and other organic liquids, abso- 

 lute alcohol being easily prepared by its use; to 

 deoxidize and carbonize iron, and as a reducing 

 agent in fire assays. Moissan has used it as a 

 reducing agent in the preparation of other car- 

 bides. 



Mr. Pennock' s paper gave interesting particu- 

 lars out of the construction of the coke ovens 

 at Syracuse, N. Y. , with details of the percent- 

 ages of bye-products, composition of the gas, 

 tar, etc., closing with lantern views of the ex- 

 terior and interior of the buildings, showing the 

 retorts and other important parts of the plant. 

 DuRAND Woodman, 



Secretary. 



DISCUSSION AND CORRESPONDENCE. 



MESSRS. LEHMANN AND HANSEN ON TELEPATHY. 



To the Editor of Science : One or two 

 of your readers may possibly remember a 

 small exchange of words between Professor 



