SCIENCE. 



[Vol. XVI 11, No. 45 ^ 



Wants, 



A 7iy person seeking a position /or ivkich he is quali- 

 fied by his scientijic attainmeniSy or any person seeking 

 some one to fill a position of this character^ be it that 

 of a teacher o/ science^ chemist^ draughtsman, or what 

 not, 7?iay have the ' Want^ inserted under this head 

 FREE OF COST, if he Satisfies the publisher of the suit- 

 able character of his application. Any person seeking 

 information on any scientific question^ the address of 

 any sciefitific Jtian, or who can in any way use this col- 

 umn for a ptirpose consona^it with the nature of the 

 ^aper, is cordially invited to do so. 



A YOUNG- MAN with an M.S. degree from Cornell 

 University desires a position as Professor or 

 Instructor in Physics or Electrical Engineering, 



Address r " " ^'' ^r. t „*„„„4.i.„ di„„„ 



New York 



M. V. F., care Science, 47 Lafayette Place, 



WANTED— A position as Professor of Science by 

 a teacher of experience who has taken a post- 

 graduate course in biology. Address BOTANIST, 

 care Science, 47 Lafayette Place, New York. 



WANTED— A position in a college to teach Geol- 

 ogy, Mineralogy, and Physical Geography by 

 a graduate of ■" " "' " ^ ^ - -^ 



of experience. 



., scientific institution and a teacher 

 Address Box 13, Nantasket, Mass. 



WANTED, Geological Reports of State of New 

 Jersey from 1868 on, except 1880 and- 1881. D. T. 

 Marshall, Metuchen, N.J. 



WANTED— A position at a Universily as Lecturer 

 on Physical Geography or kindred subjects, by 

 a graduate from abroad. First-class references. For 

 particulars address P. A. V., care Science. 



WANTED a position as professor of geology or 

 metallursy by a school of mines graduate. Ad- 

 dress T. W. O., 49th Street and Madison Avenue, 

 New York City. 



A SCHOOL, in a charming location, needs a lady 

 teacher who would teach a portion of each 

 day, five days a week, in return for her home in 

 the institution for a year. The ordinary English 

 branches. (She will be specially acceptable if she 

 has any accomplishments, as Music, Art, Delsarte 

 System.) MALE SCHOOL, care Science, 47 Lafayette 

 Place, New York. 



A PROFESSOR, native Frenchman, would accept 

 a situation as companion-tutor in a family 

 spending the summer in the country or abroad. Best 

 pure Parisian accent. Rare opportunity to improve 

 thoroughly the acquaintance laboriously acquired 

 during the winter. First-class references. Address 

 PROP. CATEAUX, Poughkeepsie, N. Y. 



Exchanges. 



[Free of charge to all, if of satisfactory character. 

 Address N. D. C. Hodges, 47 Lafayette Place, New 

 York.l 



I have five vols, of "Olhausen's Biblical Commentary 

 on the New Testament" that I would like to sell or 

 exchange for works on geology of North America. 



These volumes are as good as new, except the slight 

 fading of the black cloth covers. D. T. Marshall, Me- 

 tuchen, N. J. 



For sale or exchange, extra hne pair {$ and ¥ ) of skins 

 of Rocky Mountain Goat, with the skulls, etc., as needed 

 for mounting; collection of vertebrate fossils from the 

 Coup Fork Tertiary of Kansas ; collection of works on 

 descriptive cryptogamic botany — mostly on Fungi: thir- 

 teen vols, of Botanical Gazette, eight vols. Qrevillea, 

 four vols. Notarisea; stereopticon outfit, with attach- 

 ment for microscopic projection ; 148 stereopticon slides, 

 illustrating zoology and cryptogams. Wanted— A merit 

 and foreign works and pamphlets on Vertebrate False, 

 tology. and series of A m. Jour, of Science and other pi 

 odicals containing contributions to Vertebrate False, 

 tology. Prof. F. W. Cragin, Topeka, Kan. 



lical specimens for exchange.— Special pains h; 



table specimens fit for 

 : offered. E. E. Eogue, 



[ice, an elaborate micro- 

 mocular objectives, one- 

 four-tenths, and three 

 le-fourth and one inch 



Spencer. Four eye-pieces. Objectives are the best made. 



Address Mrs. Marion Smith, 41 Branch Street, Lowell, 



Mass. 



For Exchange. — A collector of twelve years experience 



has many fine duplicate minerals which he would like to 



.exchange for others. Address John HoU. Rollo, Wil- 



(mington, Del. 



been taken to procure good 

 any herbarium and no other 

 Orwell. Ohio. 



For exchange or sale at a sa 

 scope outfit. Bullock stand; 

 sixth homeogeneous immersic 

 inch, Bausch & Lomb, also 



fflacmillan & Co.'s New Scientific Books. 



^xist T\iblislied. 8vo. $4.00. 



THE HISTORY OF HUMAN MARRIAGE. By Edward Westermarck, Ph.D., Lect- 



urer on Sociology at the University of Helsingfors. With a preface by Dr. A. R. 



Wallace. 8vo. $4.00. 



A treatise based upon exhaustive research, in the course of which the author has been led to adopt 

 conclusions somewhat difEerent from those put forward by Tyler, MacLennan, and other previous writers 

 on this important subject. 



New and Cheaper Edition. IStno. Clothf $2,00, 



ESSAYS UPON HEREDITY AND KINDRED BIOLOGICAL PROBLEMS. By 



D. August Weismann, Professoi' in the University of Freiburg in Breisgau. Vol. I. 

 Edited by Edward B. Poulton, F.R.S., F.L.S., F.G.S.; Selmer Schonland, Ph.D.; 

 and Arthur E. Shipley, M.A., F.L.S. 12mo. Cloth, $3.00. 



Just Published. , 



MAMMALS, LIVING AND EXTINCT. By William Henry Flower, C.B., F.E.S., 

 D.C.L., Director of the Natural History Departments, British Museum, and Eichard 

 Lydbcker, B.A. 8vo, 779 pages, with 357 Illustrations. Cloth, $6.00. 



OUTLINES OF PSYCHOLOGY. By Harald Hoffding, Professor at, the University 



of Copenhagen. Translated by Mary E. Lowndes. 12mo. Cloth, $1.50. 



CONTENTS.— Sabjeot and Method of Psychology— Mind and Body— The Conscious and the Uncon- 

 scious— ClassifLcation of the Psychological Elements— The Psychology of Cognition— The Psychology of 

 Feeling- The Psychology of the Will. 



LESSONS IN APPLIED MECHANICS. By Jambs H. Cotterill, F.R S,, and Henry 



Slade, R.N. Illustrated. 16mo. $1.35. 



"The work is elementary in character, and is designed especially to meet the wants of junior students 

 in engineering, and others commencing the study. We recommend the book as one of the best small 

 treatises on the subject.'" — Engineering and Mining Journal. 



MIXED METALS : OR, METALLIC ALLOYS. By Arthur H. Hiorns, Principal of 

 School of Metallurgy, Birmingham and Midland Institute. 16mo. With Illustrations, 

 $1.50. 

 "It is a very compact, interesting, and valuable little treatise." — Metal Worker. 



THE MYOLOGY OF THE RAVEN (Corvus corax sineratus). A Guide to the Study 



of the Muscular System in Birds. By E. W. Shtjfbldt. With numerous Illustrations. 



8vo. $4.00. 



" Is worthy of its able, diligent author, and a credit to the scientific workers of this country." — Journal 

 of Comparative Medicine and Veterinary Archives. 



New Uniform Edition of AI,FSED BUSSHZ WAIiZACJE' S Works. 



CONTRIBUTIONS TO THE THEORY OF NATURAL SELECTION : and Tropi- 

 cal Nature and other Essays. By Alfred Eussel Wallace, LL.D., F.L.S. New 

 Edition. 12mo. $1.75. 



DARWINISM. An Exposition of the Theory of Natural Selection, with some of 



its Applications. By Alfred Eussel Wallace, LL.D., F.L.S., author of "The 



Malay Archipelago," etc. With Map, Portrait, and Illustrations. 13mo. $1.75. 



" The present work contains the conclusions upon this great subject of thirty years of thought and ob- 

 servation. ... A contribution of the first importance to the literature of the subject."— iv; F. Times. 



*Macmillan & Co.^s New Complete Catalogue will be sent free by mail to any address on application. 



MACMILLAN & CO., 112 Fourth Ave., N. Y. 



SCIENCE CLUBBING RATES. 



10^ DISCOUNT. 



We will allow the above discount to any 

 subscriber to Science who will send us an 

 order for periodicals exceeding $10, counting 

 each at its full price. 



N. D, C. HODGES, 47 Lafayette Place, N. Y. 



OFWHAT USE IS THAT PLANT? 



You can find the answer in 



SMITH'S "DICTIONARY OF 

 ECONOMIC PLANTS." 



Sent postaid on receipt of $3.80. Publish- 

 er's price, $3.50. 



SCIENCE BOOK AGENCY, 



47 liafayette Place, Tiew "Sorb 



Minerals, 



Rocks, 



Fossils, 



Casts of Fossils, 



Geolog^ical 



Relief Maps, 



Ward'sNatural Science Establishment 



Mineralogy, Geology, Paleontology, Zoology, Osteology, Anatomy. 



Send for Circular. ROCHESTER, N. Y. 



iStnffed Animals 



and Skins, 



Mounted 



Skeletons, 



Anatomical 



Models, 



Invertebrates 



