220 



THE AMERICAN MONTHLY. 



[November, 



electro-plated with gold by Dr. A. Y. 

 Moore, of Cleveland. The slide was not 

 only strikingly beautiful, as seen under 

 the binocular microscope with a ^-inch 

 objective, but the plating process was evi- 

 dently of value in rendering the markings 

 more distinct. In this particular case, the 

 true elevation of the radial costas was much 

 more obvious than in the natural diatom. 

 A. H. Breckenfeld, Rec. Seer. 



Richmond (Va.) Microscopical Soci- 

 ety. 



In one of the recent meetings of the 

 Society Mr. Christian exhibited an inter- 

 esting test slide (his own preparation) in- 

 geniously mounted, with a view to dis- 

 cover any astigmatism of the eye. It 

 consists partially of diatoms of the Xa- 

 viciila shape. If the eye of the observer 

 can see simultaneously all the lines of the 

 objects in the field well defined and 

 resolved, then his eye is practically with- 

 out astigmatic defect. 



The object of the important test-slide is 

 very obvious, as incomplete perceptions 

 are often erroneously attributed to the 

 inferiority of the objective used, when in 

 fact they are the result of an astigmatic 

 defect in the observer's eye. Results of 

 observations among microscopists often 

 differ because the operators of instruments 

 are frequently not aware of the astigmatic 

 condition of their eyes. 



NOTICES OF BOOKS. 



Microscopical Records, based upon a plan 

 presented by Prof. S. H. Gage, B. S., at a 

 meeting of the American Society of Mi- 

 croscopists held in Chicago in 1883. By 

 Chas. E. Ailing. Rochester, N. Y., 1886. 

 This work is a blank book with spaces 

 for entry of all items which require to be 

 preserved of the treatment of microscopic 

 objects. Blank spaces are provided, num- 

 bered, and spaced for the insertion of 

 common name, specific name, locality, col- 

 lector, preparator, method of hardening, 

 staining, clearing, mounting, date, and 

 remarks. There is also an alphabetical 

 index at the back of the book, and blank 

 pages for recording various formulae. 



The book is handsomely gotten up, 

 bound in half Russia, with spring back, 

 and sells for $3.00 or $4.00, according as 

 there is space for 500 or 1,000 catalogue 

 numbers. It is worthy of hearty com- 

 mendation, and has been well received. 

 Something of the sort should be a part of 



every collection of objects, and this is the 

 neatest thing of its kind which we know 

 anything about. 



Wells, S.; Treat, Mary ; and Sargent, T. 

 Leroy: Through a microscope : some- 

 thing of the science, together with many 

 curious observations, indoor and out, » 

 and directions for a home-made micro- 

 scope. Chic, The Inter-State Pub. Co., 

 [1886.] 3-126 p. il. S. cl., 60c. 

 The Methods of Bacteriological hivesti- 

 gation, by Dr. F. Hueppe. Translated 

 by N. M. Biggs, M. D. N. Y.; D. Ap- 

 pleton & Co.; pp. 218; 31 wood-cuts; 

 1886. 



The author has attempted to supply the 

 want of a complete and comprehensive 

 representation of the methods of bacterio- 

 logical investigation, acting under the wish 

 of Geheimrath Koch, his teacher. 



The work treats, under separate chap- 

 ters, of — I. Spontaneous generation, and 

 the principle of sterilization. 2. Forms 

 of bacteria and microscopical technique. 

 3. Culture methods. 4. Inoculations for 

 the determination of the causal relation 

 of bacteria growth to decomposition and 

 disease. 5. General biological problems. 

 6. Special hygienic investigation. 7. Bac- 

 teriology as an object of instruction. 



The book is both descriptive and criti- 

 cal. It gives, with description of the 

 author's methods and views, the methods 

 of others, with abundant references to 

 their writings, and is historical in its mode 

 of treatment. The chapter upon micro- 

 scopical technique, clear and full (pp. 

 28-92), giving classification of the bacteria, 

 full directions for staining and cover-glass 

 preparation ; this, and the chapter on cul- 

 ture methods, will be described in greater 

 detail in another place in this Journal. 



Exchanges. 



[Exchanges are inserted in this column without 

 charge. They will be strictly limited to mounted ob- 

 jects, and material for mounting,] 



Labels for slides, also slides and material to ex- 

 change for same. EUGENE PINCKNEY. 



Dixon, 111. 



For Exchange : Seeds of Orthocarpus purpurascens 

 and Orthocarpus attenuatus, and slides of same, in ex- 

 change for goori objects, foraminifera preferred. 



EDWARD GRAY, M. D., Benicia, Cal. 



Infusorial Earth from Saco, Me., in exchange for 

 slides of Volvox globator, or Spines of foreign sea- 

 urchins. 



D. E. OWEN, Brunswick, Maine. 



Pathological and Histological Slides (very fine) in 

 exchange for other good slides. 



F. M. HOYT, 

 160 Washington Park, Brooklyn, N. Y. 



