1646 Journal of Applied Microscopy 



one at a trifling cost. It consists of a circular board about twelve inches in 

 diameter, on the radii of which are fastened a number of trough-like tin pieces. 

 These tin pieces (Fig. 1) are open at each end and just large enough to allow 

 suitable sized cylindrical vials to be pushed in with sufficient friction to hold 

 them securely. The specimens are placed in the vials in the desired fluid. 

 The vials are securely corked and placed in the tin troughs on the wheel. The 

 wheel is made to revolve slowly in a vertical plane by any desired method. 

 This causes a complete stirring or mixing of the fluid and the specimen is very 

 soon saturated with it. 



The writer has made use of a water moter for the power and an old clock 

 gear to reduce the speed. The balance wheel of the clock was removed and a 

 pulley wheel put on the shaft of the escapement. This pulley connects by a belt 

 with the water motor. The revolving disk, or wheel, is attached to the winding 

 shaft. A moderate speed of the water motor will thus be reduced to one or two 

 revolutions of the large wheel per minute. This is fast enough to cause sufficient 

 mixing of the fluid without causing any damage to the tissue. The apparatus 

 runs so slowly that the fluids are free from violent agitation. The most delicate 

 tissue may be thus handled with safety. James Rollin Slonaker. 



University of Chicago. 



Oculars for General Laboratory Work. 



The microscopes intended for general laboratory work, as for example the 

 BB4, are usually furnished with the two-inch and one-inch eyepieces. The 

 writer, as an experiment, ordered two instruments of this kind, substituting 

 the three-fourths-inch eyepiece for the one-inch. The results were very gratify- 

 ing. The one-sixth objective is not at all overtaxed by the use of the three- 

 fourths-inch eyepiece, and the gain in magnification is considerable. The range 

 of the four magnifications possible with two objectives qnd two oculars is greater 

 and more suitable for general work. The results following the use of the three- 

 fourths-inch eyepiece are especially noticeable in the study of minute objects, as 

 fungus spores, bacteria, rhizoids, etc. It is the opinion of the writer that when 

 only two eyepieces are used, for general work they should be the two-inch and 

 the three-fourths-inch. John H. Schaffner. 



Ohio State University. 



The present number of the Journal contains a careful review of the '2"Jnd 

 volume of the Transactions of the Atnerica?i Microscopical Society. We learn that 

 the 23d volume is now in press, and may be expected in the early spring. 

 There has been a noticeable increase in the membership of the society, and the 

 completion of the Spencer-Tolles Fund, which leaves an annual sum free for the 

 encouragement of research, is certainly an effective influence in bringing strong 

 members into the organization. 



