1877.] Microsvopy. 379 
giz inch) are preferred, of the size adopted by Fuess ot Berlin (134 by 
15 inch), and these, with covers of medium thinness and { inch square, 
will be used unless otherwise ordered. 
A New Stupents’ Microscorr. — The increasing importance of 
cheap and portable microscopes, and the increasing demand for good in- 
struments specially adapted to work in histology and pathology, has 
lately led all our prominent makers to introduce so-called students’ mi- 
croscopes of excellent quality and remarkable cheapness. The latest 
work of this kind is the new students’ microscope of Mr. Joseph Zent- 
mayer, of 147 South Fourth St., Philadelphia. This stand is a truly 
American model, in which the standard English and continental styles 
which have served as models so long, are nearly lost sight of, and the 
recent very important contrivances of Mr. Zentmayer are introduced 
almost as effectively as in his superb first class stand. The base and 
hollow upright column are cast in one piece, giving great lightness and 
firmness combined. The mirrors and substage, together, swing around 
the object, so that it can be readily kept in focus of the illuminating 
apparatus at any desired angle; and the bar can be swung so as to carry 
the whole illuminating apparatus above the stage for opaque objects. 
There is a good substage which can easily be removed entirely when de- 
sired. The stage is thin and beveled, so that extreme obliquity of 
illumination can be obtained by simply turning the stand or swinging 
the mirror. The diaphragms are mounted on the substage, and can be 
brought up close to the object-slide if desired. The coarse adjustment 
is by a sliding tube, and the fine adjustment by a screw and lever mov- 
ing the whole body on a long sliding support exactly like that of the 
rack movement in the common Jackson stands. The stage is only 
three inches from the table, and the tube is correspondingly short, 
though capable of lengthening by draw-tube to the standard length. 
The whole stand is a marvel of neatness, compactness, stability, and con- 
venience. At the request of the writer, a stand has been made with a 
Specially adapted achromatic condenser and with a thin concentrically 
revolving stage like the diatom stage of the maker’s “\centennial” stand, 
which is worthy of being furnished with the highest class objectives and 
` is capable of doing almost anything that the most elaborate stands 
can do. 
Practica Mrcroscory. — Rey. E. C. Bolles, an unsurpassed lect- 
urer on the subject, has consented to give instruction in microscopy at 
the second session of the summer school of biology, which will be 
` Opened at the Museum of the Peabody Academy of Science, at Salem, 
Mass., on the 7th of July next. The term lasts seven weeks. A course 
of lectures and demonstrations on Animal Histology, will also be given 
by Mr. C. S. Minot. The admission fee is $15.00. 
Boston Microscoricat Socrety.— This society held its second 
annual reception on Friday evening, April 27, with a programme of re- _ 
