120 THE AMERICAN MONTHLY. [May. 



Too much cannot be said in praise of Mr. Kunz's text, which pre- 

 sents a world of interesting facts about precious stones and their rela- 

 tions to mineralogy and archgeology in a way attractive not only to those 

 whose interest in the subject is confined to its scientific side, but also to 

 those who look to the book for entertainment. Yet it is not fiction 

 with which Mr. Kuntz deals but an exact record, begun in 1882 for 

 the report of the Division of Mining Statistics, and supplemented by 

 travel and investigation. 



The volume is a chef d'ceuvre of the printer's and engraver's arts. 

 The superb colored chromo-lithographic plates illustrating especially 

 fine and typical specimens, by Messrs. Prang & Co., are unquestion- 

 ably the finest of their kind ever published. We readily recommend 

 this magnificent volume to all interested in the subject. 



SUBSCRIBERS' NOTICES. 



[These notices will be given six insertions in this column at 25 cents per line or fraction thereof.] 



WANTED.— Vol. VII, No. 2 (F'eb., 1886), of American Monthly Microscopical Journal. 



A. G. YOUNG, State House, Augusta, Me. 



WANTED. — Diatom material from America, Australia, and Asia in exchange for fossil and recent 

 material from Denmark. 



CHR. MICHELSEN, 33 Nedergade, Odense, Denmark. 



FOR EXCHANGE. — Slides of diatoms from peat bogs in Boston, Mass. 



F, F. FORBES, Hrookline, Mass. 



WANTED. — Vol. I, American Monthly Microscopical Journal. 



C. K. WELLS, Marietta, Ohio. 



WANTED TO PURCHASE. — Histological slides from normal tissues of mammals, prepared with 

 a view to show the size of the " cells," incases where the age of the animal-subject is definitely known, 

 as bearing on the question of a supposed diminution in the size of cells in aging organisms, correspond- 

 ing to a similar decrease, reported by Balbiani and Maupas in aged unicellular life. Address, 



C. A. STEPHENS' LABORATORY, Norway Lake, Maine. 



WANTED. — Diatomaceous material of good quality, fossil and recent. I offer diatom slides or 

 photo-micrographs in exchange. 



D. B. WARD, Poughkeepsie, N. Y. 



OFFERED. — Diatomaceous Earth from Utah (Desert) for Histological Mounts. 



PROF. ORSON HOWARD, Salt Lake City, Utah. 



CORRESPONDENCE invited with a view to the exchange of either mounted or unmounted Oribatida 

 (British) for American species. E. BOSTOCK, Stone, Staffordshire. 



WANTED. — Any works on Microscopy not already in my Library. 



H. M. WHELPLEY, F. R. M. S., St. Louis, Mo. 



First-class Histological Slides for other good mounts : Histological and Pathological material cut on 

 hares. S. G. SHANKS, M. D., 547 Clinton Ave., Albany, N. Y. 



FOR SALE OR EXCHANGE. — Mosquitoes, male and female. Price 75 cents each. Will ex- 

 change only for first-class mounts. E. W. SHARP, 2800 Richmond St., Philadelphia, Pa. 



A $5 MICROSCOPE. — Made on proper scientific principles. Magnifies 100 diameters or 10,000 

 times. For other interesting articles send for list of Popular Scientific Specialties. 



G. S. WOOLMAN, 116 Fulton St., New York. 



SPECIAL BARGAIN in histological slides. 



WM. N. BEGGS, M. D., 2207 Sidney St., St. Louis, Mo. 



FOR SALE OR EXCHANGE. — Photo-micrographs of P. angulatum taken through Spencer's 

 ^ H. I., 2400 diameters. Also photo-micrographs of bacteria, diatoms, etc.. 25 cents each. Will ex- 

 hange for well-mounted slides. Dr. J. E. BAKER, Wyoming, Ohio. 



TO MICROSCOPISTS. — After July i the price of my well-known slides will be the uniform one of 

 50c. each, ;Js.oo per dozen. Send 2c. stamp for catalogue and 50c. for slide of Podura scales, test, or 

 other diatoms, or of miscellaneous objects. Thum's " > h. My !" slides of arranged diatoms, gorgeous 

 butterfly scales, etc., at lowest rates. 



M. A. BOOTH, F. R. M. S., Longmeadow, Mass. 



