ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



651 



a complete rotation. The rectangular movements are delicate and actuated 

 by two milled heads, placed one above the other (Turrell form). The upper 

 part of the stage is polished black glass ; the edge is milled, graduated to 

 degrees and silvered. 



Fig. 172. 



Fig. 172 can be adapted to any Microscope which will admit of a 

 stage 3^ in. in diameter. The movements are all contained on the upper 

 surface of the stage, and it can therefore be completely rotated. It is thin 

 and will admit the use of very oblique light. 



Smirnow's Mierostat.* — Dr. A. Smirnow describes, under the name of 

 microstat, an apparatus which he has constructed to obviate the great 



Fio. 173. 



inconvenience of examining the whole of a large object under high powers, 

 or of re-finding minute objects, such as Bacteria, in a large preparation. 

 The purpose of the instrument is much the same, he notes, as that of KlQnne 

 and Muller's Bacterium finder. 



The principle of the contrivance is based on the fact that any point 



* Russ. Med., 1886, No 27 (in RussianX Arch. f. Mikr. Anat., xxix. (1887) pp. 384-8 

 (1 fig.)- 



2 U 2 



