140 THE AMERICAN MONTHLY. (July. 
count of the discovery, its principles, and mode of application. No physician who 
is informed upon the advances made in his profession can afford to pass this treat- 
ment unnoticed. We are not prepared to assert that it is a success, but it is worth a 
fair trial before it is cast aside. 
On the Use of the Microscope in Determining the Sanitary Value of Potable Waters. 
(pp. 25). Rochester, N. Y. 1887. i 
How to Study the Biology of a Water Supply. (pp. 19). ‘By Geo. W. Raftor. 
Rochester, N. Y. 1887. 
In these two papers the writer considers the methods of studying water supplies 
biologically. He declares himself in favor of comparatively simple apparatus. ‘ Very 
wide-angled immersion lenses * * * add tothe amount of time required for an ex- 
amination.’ After repeated trials, he prefers, as a life slide, ‘a plain slide with a ring 
of cement and a cover-glass.’ Other cells are mentioned; some of them described, 
and their merits brought out. A good sub-stage condenser is an indispensable appa- 
ratus for collecting aquatic forms, both animal and plant. Modes of cleaning and 
mounting are described. The forms found contaminating drinking-water are briefly 
and summarily enumerated. An outline is presented in the form of a series of sug- 
gestive questions, and the writer urges that ‘a year’s study of the water supply ’ would 
furnish a ‘fascinating and prolific field of study.’ The papers are two papers read by 
a professional civil engineer before the Rochester Academy of Science. They are 
interesting and profitable reading, with references enough to fuller accounts to make 
them a valuable guide for any one who should care to commence upon study in that 
very interesting direction. 
Some New and Rare Diatoms. By Walker & Chase.. (12 pp., 3 pls.) Flint, Mich., 
1887. 
Under the above title comes a fascicle of plates, three in number, with twelve pages 
of descriptive text. The figures are photographs from rare or new diatoms and are 
very highly commendable. In all forty-one forms are represented. Many are very fine 
as photomicrographs. Some have apparently been touched up with the pen-point, 
but many are evidently unchanged from the photograph, and are almost as clear as 
the original object must have been. The text is a series of brief notes (dated January, 
1887) upon the forms represented. These give references to original descriptions when 
the forms are not new, also the habitat notes on specific characters. 
The fascicle forms series two and three of a more extended work. We can recom- 
mend it to diatom workers. Who may apply can doubtless find out price and extent 
of the proposed work by writing to H. H. Chase, M. D., Linden, Michigan, or W. C. 
Walker, Utica, New York. 
Exchanges. 
[Exchanges are inserted in this column without charge. They will be strictly limited to mounted objects, and 
material for mounting. } . 
Diatoms Syxedra superba in situ upon alga (Ceramium rubrum) in exchange for good ‘mounted slides in 
animal histology. HENRY L. OSBORN, Lafayette, Ind. 
Wanted, earths, recent diatoms, and miscellaneous objects for mounting. Only first-class material offered or 
desired. M. A. BOOTH, Longmeadow, Mass. 
Wanted, exchange of slides, and correspondence on unusual urinary products. 
J. M. ADAMS, Watertown, N. Y. 
Ten selections of cleaned Marine Gulf Diatoms, and 100 lbs. Gulf Marine Diatom Muds. Correspondence 
invited from any one. K. M. CUNNINGHAM, 
Land Office M. & O. R.R. Co., Mobile, Ala. 
Pathological and Histological Slides (very fine) in exchange for other good slides. 
F. M. HOYT, 160 Washington Park, Brooklyn, N. Y. 
Correspondence with animal histologists with regard to exchanges solicited. 
HENRY L. OSBORN, Lafayette, Ind. 
Publisher’s Notices.—All communications, exchanges, etc., should be addressed to Henry Leslie 
Osborn, Lafayette, Indiana, Purdue University. ! 
Subscriptions, and all matters of business, should be addressed to the Business Manager, P. O. Box 
630, Washington, D. C. The address of Mr. R. Hitchcock is Osaka, Japan. 
Subscription price $1.00 PER YEAR strictly in advance. All subscriptions begin with the Fanuary 
nuntber. A pink wrapper indicates that the subscription has expired. 
Remittances should be made by postal notes, money orders, or by money sent in registered letters. Drafts 
should be made payable in Washington, New York, Boston, or Philadelphia, to the order of the Business 
Manager. The regular receipt of the JouRNAL, which is issued on the 15th of each month, will be an acknowl- 
edgment of payment. 
The first volume, 1880, is entirely out of print. The succeeding volumes will be sent by the publisher for 
the following prices which are net :—Vol. II (1881) complete, $1.50; Vol. III (1882), out of print; Vol. IV 
(1883) complete, $1.50; Vol. V (1884) complete, $1.50; Vol. V (1884), Nos. 2-12, $1.00; Vol. VI (1885), $1.50, 
Vol. VII (1886), $2.00. 2 
