I20 



THE AMERICAN MONTHLY 



[June, 1883. 



MICROSCOPICAL SOCIETIES. 



At the annual meeting of the State 

 Microscopical Society of Illinois, held at 

 the Academy of Sciences, No. 263 Wabash 

 Ave., on Friday evening, April 27th., the 

 following officers were elected : Presi- 

 dent, Dr. Lester Curtis ; ist. Vice Presi- 

 dent, Prof. E. J. Hill ; 2nd. Vice Presi- 

 dent, Dr. F. W. Mercer ; Recording 

 Secretary, William Hoskins ; Corres- 

 ponding Secretary, C. S. Fellows ; Treas- 

 urer, W. H. Summers ; Trustees, B. F. 

 Nourse, C. O. Boring, B. W. Thomas, 

 W. H. Bullock and H. A. Johnson, M. D. 



At a meeting of the New York 

 Microscopical Society held April 20th, 

 Mr. A. A. Julien reported on the subject 

 of Microscopical Mineralogy. Among the 

 most interesting slides which he exhibited 

 and explained, in illustration of his sub- 

 ject, were liquid carbonic acid gas inclu- 

 sions in Quartz crystal. He spoke of the 

 importance of not exposing the inclusions 

 to the heat of the lamp as reflected from 

 the microscope mirror, for more than a 

 few moments at a time, since a longer ex- 

 posure converts the liquid into a gas, thus 

 rendering the object invisible. 



NOTICES OF BOOKS. 



A Manual of Photographic Chemistry^ 

 Theoretical and Practical. By Rev. T. 

 Frederick Hardwich, M. A. Ninth Edi- 

 tion, edited by J. Trail Taylor, editor 

 of the " Photographic Times and 

 American Photographer," member of 

 various societies, etc. New York : 

 Scovill Manufacturing Co., 419 & 421 

 Broome St. 1883. (i2mo pp. 464.) 



For those who desire to know morfe 

 about the chemistry of photographic 

 operations than is found in the ordinary 

 elementary books for the instruction of 

 amateurs, this work can be most highly 

 recommended. 



Both collodion and gelatin processes 

 are treated at length, and in truth it may 

 be said that the work is a treatise on 

 photography as well as a manual of photo- 

 graphic chemistry. It is to amateurs 

 that we are indebted for many valuable 

 improvements in photography, and the 

 publication of this book — the popularity 



of which is evident from its having reached 

 a ninth edition — has undoubtedly opened 

 the way to many of them, by indicating 

 the direction in which experiments might 

 be profitably conducted. 



The plan of the work is a good one. 

 The different chemicals employed are 

 first described ; then follows an account 

 of the action of light on salts of silver, 

 the development of the invisible image, 

 and then a great deal of information about 

 different photographic processes in gen- 

 eral. The book is written for photographers, 

 who are not persumed to be chemists, 

 hence it is adapted to the understanding 

 of all readers. 



In the last part of the work is the most 

 complete treatise, of a strictly elementary 

 and popular character, .on the optics of 

 photographic apparatus, to be found. In 

 this part we think we discover the 

 work of the able editor who is an ac- 

 knowledged authority upon that subject, 

 as well as upon all other matters relating 

 to photography. 



Exchanges. 



Wanted. — Trichina Spiralis, Pleurosigma Ang., or 

 other well-mounted slides in exchange for fine slides. 

 Insects, Acan, Spermatozoa of Horse, Physiological 

 and Pathological preparations. J. O. Stillson, M. D.. 

 504 Upper Second Street, Evansville, Ind. 



For Exchange. — Well-mounted double -stained vege- 

 table preparations, also, a few first-cla,ss injected prepar- 

 ations for other well-mounted slides. N. A. Richards, 

 St. Louis, Mich. 



Well-mounted slides of Polycystina, transparent and 

 opaque, for any well-mounted slide. P. C. Cole, M.D., 

 254 West Forty-second .Street, New York, N. Y. 



Wanted. — Slides of Bacteria in exchange for other 

 slides, or for cash. J. M. Adams, Watertown, N. Y. 



Wanted. — I will give a good type slide of diatoms, 

 or a slide of arranged diatoms, for a gathering of /^/«<»'(?- 

 sigma angulatum. Thos. Christian, 108 Virginia St., 

 Richmond, Va. 



DiATOMACEOus MATERIAL and Histologicai slides 

 for other well-mounted and named slides of Foramini- 

 fera. Animal Parasites, Pathological subjects, etc. R. 

 Cauch, M.D., Carpenteria, Cal. 



FosiL Diatoms from Carson, Nev., and Posa Creek, 

 Cal., shdes or material to exchange for good diatoms, 

 mounted or material. Also, many other diatoms; lists 

 exchanged. The above deposits are rich and newly dis- 

 covered by myself. F. H. Engels, M.D., Virginia, Nev. 



