eSCIENCE 
SINGLE COPIES, 15 cts. 
VoL. VI. No. 146. Fr RIDAY, OcTOBER 15, 1897. ANNUAL SUBSCRIPTION, $5.00. 
GENERAL ELECTRIC Co.’S 
NEW X-RAY TUBE 
WITH AUTOMATIC VACUUM REGULATOR. 
Simple. Efficient. Long-lived. Cannot run too high in vacuum. 
CACASCAOULHLALD 
Roentgen Ray Apparatus, catalogue No. 9,050. Minia- 
ture, Candelabra, Decorative Lamps, catalogue No. 9,044. 
BASASADLTHLASS 
Edison Decorative and Mintature Lamp Department, 
(GENERAL ELECTRIC COMPANY), 
HARRISON, N. J. 
NEW CATALOGUE. ANNALS 
OF THE 
We have recently issued a new edition, revised and en- 
larged to 64 pages, of our catalogue of INSTITUTE OF JAMAICA. 
Books on Chemistry, Chemical Vol.1. No.1. September, 1897. 
Technology and Physics. pore asl al 
wlgegmengel gape mcaee lhe tpaes | LIST OR THE DBCAPOD CRUSTACEA OF JAMAICE 
cent literature up to date. By MARY J. RATHBUN, U. S. National Museum. 
A copy of this Catalogue will be sent free by mail to any ie ee TS 
address. TO BE OBTAINED FROM THE 
INSTITUTE OF JAMAICA, Kingston, Jamaica, 
D. Van Nostrand Company, AND FROM 17s AGENTS 
Publishers and Importers of Scientific Books, H. SOTHERAN & CO., 140 Strand, W. C., London. 
G. P. PUTNAM’S SONS, 27-29 West 23d St., New York. 
46 PP. 4T0. PRICE, ONE SHILLING. 
Physical, Chemioal, Microscopioal» Zletrical Annaratus 
Established 4 COMPLETE LABORATORY EQUIPMENT OF OUR OWN MANUFACTURE. incorporated 
1882. X-RAY APPARATUS AND CROOKE’S TUBES A SPECIALTY, 1894. 
Catalogue P Free to School ZIEGLER ELECTRIC co., “Duty Free” Importations from 
Officials and Science Teachers. 141 Franklin St., BOSTON, MASS. Foreign Manufacturers. 
23 Murray St. and 27 Warren St., New York. 
