20 



THE AMERICAN MONTHLY 



[Jan., 18S2. 



opening in the screw. This opening, 

 therefore, acts as a diaphragm. In order 

 to secure the benefit of the full aperture ; 

 the back of the objective can be removed 

 and an adapter, furnished with the Butter- 

 field broad-gauge screw, can be sub- 

 stituted. It has also another screw of 

 about the same diameter as the Butter- 

 field screw, but provided with a finer 

 thread. The front of the objective is 

 ground down to a conical shape. For 

 ordinary use, this front is covered with 

 a brass cap, having an aperture in the 

 centre to allow the conical end of the 

 object to pass through. The cap can be 

 removed when it is desired to use the ob- 

 jective for the examination of opaque 

 objects. It resolves angulatum very satis- 

 factorily, and bears eye-piecing extreniely 

 well, working admirably on anatomical 

 structures. ' 



Mr. E. B. Stuart exhibited a Hitchcock 

 lamp,* which he stated commended itself 

 to the use of microscopists. No chimney 

 is required, it being a blast lamp, the 

 flame of which is fanned by a current 

 of air from the bottom. He also showed 

 under the microscope, specimens of the 

 gelatin-bromide plates for photographic 

 work, that had been submitted by a 

 photographer as imperfect. An inspec- 

 tion under the microscope showed three 

 kinds of spots : one caused by par- 

 ticles of dust which had settled on the 

 gelatin, while still soft, and as the emul- 

 sion hardened, became firmly fixed on the 

 plate. The second kind of spots were 

 apparantly caused by the solvent action 

 of some substance on the film, as it could 

 be seen to be less dense at those points, 

 while the third were thicker and evidently 

 caused by carelessly spattering the emul- 

 sion on partially dried plates. 



The regular monthly meeting of the 

 Elmira Society was held November 24th, 

 with President Gleason in the chair, and 

 twenty-five members and thirty-two visi- 

 tors present. 



Dr. Krackowizer spoke extemporaneous- 

 ly upon " Histological facts, where to 

 look for them, and how to find them." 



He explained cell differentiation from 

 the simple protoplasmic unit, to the vast 

 and complicated congregation of them in 

 the human body. He clearly showed, by 

 means of the black-board, the integral 

 parts, as well as the entire woof of such 

 tissues as the skin, mucous membrane, 

 liver, kidney, etc., showing where their 



* We regret that we cannot lay claim to 

 any credit for this patent lamp. — Ed. 



cells resembled each other, and pointing 

 out how the observer may^ distinguish 

 them. 



A brief colloquial discussion of the sub- 

 ject followed, in which Drs. Gleason, 

 Carr, Lucy, and the Secretary took part. 



Dr. Geo. E. Blackham, made the ex- 

 cellent suggestion that the members of 

 local societies should make a complete 

 list of the microscopic organisms of this 

 locality. 



Dr. Blackham said that the meeting of 

 the American Society, in Elmira, next 

 August, promised to be the largest, and 

 richest in papers, of any yet held. 



Notices of Books. 



The Galvanic Accujnulator for Storing 

 Dynamical Electricity for Cautery 

 and Illuminating Purposes. By Louis 

 Elsberg, A. M., M. D., etc., etc. New 

 York : Trow's Printing and Bookbind- 

 ing Company, 1881. (Pamphlet, pp. 13). 

 The title of this pamphlet fully de- 

 scribes its contents. An arrangement of 

 the Plants secondary battery suitable for 

 the purpose of cautery is figured and 

 described. The article is a reprint from 

 the Transactions of the New York Aca- 

 demy of Medicine. 



Exchanges. 



[Exchanges are inserted in this column without 

 charge. They will be strictly limited to mounted 

 objects, and material for mounting.] 



For a packet of frustules of Amphitetras antedi- 

 luviana, send slide, or unmounted specimen to 



K. M. CUNNINGHAM, 



Box 874, Mobile, Ala. 



A beautiful collection of wild seeds of Central Ohio 

 to exchange. List furnished on application. 



F. O. JACOBS, Newark, Ohio. 



Mounted slides of Selenites for the Polariscope, in 

 most beautiful and brilliant colors, in exchange for 

 first-class Histological and Pathological slides and 

 slides of diatoms, algse, etc., 



A. C. GOTTSCHALK, 

 193 North Salina Street, Syracuse, N. Y. 



Unmounted objects, Foraminifera, Spicules, Plant- 

 hairs, Zoophytes, etc., in exchange for other objects, 

 mounted or unmounted. 



E. PINCKNEY, Dixon, 111. 



Wanted — First-class mounts of double-stain vege- 

 table preparations in exchange for first-class insect 

 preparations. H. S. WOODMAN, 



P. O. Box 87, Brooklyn, E. D., N. Y. 



Well-mounted Histological and Pathological slides 

 in exchange for other first-class slides. 

 W. H. Bates, M.D., 184 Remsen St. Brooklyn, N. Y. 



