SCIENCE 



NEW YORK, MAY 4, li 



Single Copies, Ten Cents. 

 ^3.50 Per Year, in Advance. 



Entered at New York Post-OflBce as Second-Olass Mail-Matter. 



Editorial ...... 



Can City Roofs be used as Health-Resorts ? — E,\perimental 

 Psychology at the College de France. — Failure of Yellow- 

 Fever Inoculation. — Manual Training in Washington. 



The Pecuniary Economy of Food j^. a': Ban-eti 

 St. Petersburg Letter . . O. E. 



Scientific News in Washington. 



Manual Training in Washington . . . , 



The Yellow-Fever Germ . . . . . 



Copper, Lead, and Zinc . . . . . 



Electrical Science. 



Intensity and Consumption of Different Sources of Light 

 A New Electric Meter .... 



The Radiograph ..... 

 Storage-Batteries on the Brussels Tiamways 

 The Eickemeyer Dynamo .... 

 An Impro\ed Prony Brake . 



Health Matters. 



Choleia-Infantum and the Weather 

 Wasted Sunbeams ; Unused Housetops 



207 j Book-Reviews, 



i Exact Phonography ..... 



I European Schools of History and Politics 



Practical Geography for Schools .... 



A Laboratory Manual of Chemistry 



Skeleton Notes upon Inorganic Chemistry 



Weather ....... 



A Study of the Histological Characters of the Periosteum and 

 Peridental Membrane ..... 



The Mind of the Child ..... 



Der Tierische Magnetismus (Hypnotismus) und seine Genese 



De la Suggestion et de ses Applications k la Pedagogie 



Notes and News ..... 



20S 

 209 



210 

 211 

 2n 



212 

 212 

 212 



213 

 214 



Letters to the Editor. 



Experiments in Vision Again 



Is the Rainfall increasing on the Plains? 



Chloride of Nitrogen 



Christmas Customs in Newfoundland 



Osteological Notes 



/. H. Hyslop 



H. A. Hazen 



Ira Remsen 



W. F. Stocklev 



D. D. Slade 



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The Science Company, Publishers, /}.'/ Lafayette Place, New York. 



London agent: G. E. Stechert, 26 King; William St., Strand. 



A NEW LABORATORY MICROSCOPE. 



ixcm.i^^. 5.) 



'(/■,■< ??jning this microscope we have discarded luxuries, retaining 

 necco- ^^ °'^'/]t have regarded solidity and thorough workmanship as 

 prime featu.. ^V <->''' 'croscope intended for students' use, especially in 

 laboratory work". -. he lenses (l inch and \ inch) give a clearness of 

 definition consonant with the mechanical construction of this micro- 

 scope. 



FROM AN EMINENT HISTOLOGIST. 



Ithaca, N.Y., March ist, 1888. 

 The Acme No. 5 microscope sent for examination came duly 

 [copy.] and has been thoroughly examined by me and by representa- 

 tives of the Departments of Botany and Entomology. We 

 are all very much pleased with it. 



It seems to me that this is the best microscope for the price that I 

 have ever seen. 



(Signed) Simon H. Gage, 



Histological Laboratory, 

 Cornell University. 



Send for copy of the Microscopical Bulletin (December number) 

 containing description of this microscope and various other matters of 

 interest to the worker, including a paper by Prof. John A. Ryder on 

 " Celloidin-Paraffin Methods of Embedding," discussion of Professor 

 Minot's "Complaint," etc. 



Send also for our Catalogue of Microscopes, 67th edition. 



James W. Queen &L Company 



924 Chestnut Street, Philadelphia. 



MAKERS OF 



J THE ACME MIOROSCOFES, 



