l^lQ^y 



SCIENCE 



New Series. 



Vol. VIII. No. 194. 



Friday, September 16, 1898. 



Single Copies, 15 cts. 

 Annual Suesckiption, $6.00. 



General Electric Co.'s 



New X=Ray Tube 



WITH AUTOMATIC VACUUM REGULATOR. 



Simple. Efficient. Long-lived. Cannot run too high in vacuum. 



Roentgen Ray Apparatus, catalogue No. 9,050. Minia- 

 ture, Candelabra, Decorative Lamps, catalogue No. 9,044. 



Edisoii Decoiatlve anil piimature Lamp Depaitniiiiit, 



(.GENERAL ELECTRIC COMPANY.) 



HARRISON. N. J. 



f^ I ■■* in I ^^^ pages, 40 splendid engravings. Con- 



Complete Mineral Catalogue, ssHscssssi 



I %M classification stiowing what minerals contain 



each element. Alphabetical index ofnames. Lists giving the specimen values of minerals, etc., etc. Forteachers, students, 

 collectors, mining experts, chemists, and others. Postpaid; Pamper, 35 cents ; Cioi/i, 50 cents; Calf , interleaved^ ^1.00 , 



DR. A. E. FOOTE, 1317 Arch Street, Philadelphia, Pa, U.S.A. Esiabiishea me 



COLLECTIONS OF MINERALS FOR STUDY OR REFERENCE. CABINET SPECIMENS. 



GEMS. 



Storage Batteries ^^^^^^^»^»^^»\ 



" There is no part of the equipment of a modern labora- w 



tory which is more useful than storage cells." ^ 



■ — 3fanual of Ex2)eriments in Physics ; by Ames and Bliss. % 



There is no Storage Battery better made or more widely used than f 



the "Chloride Accumulator." ^ 



There is no one but the undersigned, specially authorized by the f 



Electric Storage Battery Co. (makers of the "Chloride Accumulator"), ^1 



to solicit Laboeatoey Oedees. ^ 



Correspondence requested. Catalogue A upon request. ^ 



James G. Biddle, 909 Drexel Building, Philadelphia 



