/<ri)9 eo 



SCIENCE 



New Series. 

 Vol. VII. No. 174. 



Friday, April 29, 1898. 



Single Copies, 15 OTS,' 

 Annual Sdbsceiftion, $5.00 



General Electric Co.'s 



New X=Ray Tube 



WITH AUTOMATIC VACUUM REQULATOR, 



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. 



Edison Decorative anil piiiilature Lam Depailnieqt, 



{GENERAL ELECTRIC COMPANY,) 



HARRISON, N. J. 



TP^ *IVr * 1 THAUJIASITE from West Paterson, N. J., a unique compound of the 



Jtw9i]?^^ AyM-T8 "nil tf^T*?8il.S» sulphate, sUicate and carbonate of calcium with 42 per cent, of water. 



An excellent, attractive, cabinet size specimen, postpaid for 14 cents, 



CBTSTALLIZED AKSENIC from Japan, in balls % to J^-inch diameter, postpaid, 16 cents. CONTACT TWINS OF 

 QUARTZ, postpaid, Sl.OO. TWISTED STIBNTTE crystals and groups, 28 cents, postpaid. MOUNTAIN LEATHER, a 

 great novelty, postpaid, lie, 16c., 22c. and 27c. 124-page Catalogue, describing every mineral, 2oe. in paper ; 60c. in cloth, 

 44-page Price-List, 4c. Bulletins and Circulars Free. 



GEO. L. ENGLISH & CO., Mineralogists, 64 £. 12tli St., New York. 



IVIAX HIOHIa^ Chemnitz^ Crerxnany^ 



FIRST EUROPEAN MAKER OF 



Physical and mectrical Instruments 



special Manufacturer of Roentgen X-Kay Outfits. 



Apparatus for Experiments w^ith Curz'ents of Higli Frequence and Tension. 



Apparatus for the Experiments according to Hertz. 



Apparatus for Marconi's Wii-eless Telegraphy. 



Price List No. 10 of Physical Instruments ; nearly 400 pages and more than 1300 engravings (in German, English 

 and French). Special List of X-Ray Apparatus containing numerous testimonials as well as estimates tor complete 

 outfits, explicit oirections for use, etc., in English language. 



^REFERENCES FROM LEADING EXPERTS. ^^^ 



Representative: Messrs. EIMER & AMEND, 205-211 Third Avenue, New York. 



