THE MICROSCOPE. 89 



annual loss from charbon was 322. Since vaccination but 11 cows 

 were lost. 



This already sufficiently demonstrates the value of the discovery 

 of, and experimentation with, the bacillus, for all of which we are 

 indebted to the microscopists. — Editorial in The Bistoury. 



A New Binocular. — The Bausch & Lomb Optical Company, 

 of this city, have just completed a binocular of the well-known 

 " Investigator " pattern, which, in addition to being as nearly per- 

 fect in other respects as possible, presents improvements in the con- 

 struction and adaptation of the prism, and in the nose-piece in 

 which the prism is fixed, that deserve attention. 



In the absence of cuts of this part of the instrument, which we 

 hope to be able to produce in our next issue, those of our readers 

 interested in this form of microscope must be content with a brief 

 outline of the leading features of the new arrangement. These are: 



1st. A very large prism with perfectly plain surfaces, cemented 

 upon a glass disk, 



2d. As this combined prism and disk is fixed by the maker, it 

 remains in place regardless of the whim of or want of skill in the 

 observer. 



3d. The mounting of this combination is a brass nose-piece, 

 which slides into the tube and is fastened by a new form of bayonet 

 catch, a novel feature in itself. 



4th. The monocular nose-piece is separate and is fastened in 

 the tube in the same manner. 



5th. The effect with the prism in place is quite as good in 

 this instrument as it is in the old forms when the prism is withdrawn, 

 as it permits the passage of light possible in objectives with the 

 society screw. 



6th. While a little more time is consumed in changing from 

 monocular to binocular and back again than is the case in the old 

 form, the loss is fully compensated for by the absolute accuracy of 

 the new, which cannot get out of place. 



7th. As low powers only are used in binocular instruments, a 

 given objective may be kept in the binocular nose-piece and the 

 higher power in the monocular, an arrangement almost as con- 

 venient as in the well-known double nose-piece. 



8th. The bayonet catch above mentioned may be applied, and 

 probably will be in the near future, to objectives as a substitute for 

 the society screw. The fit is as good, and the time saved in chang- 

 ing objectives great.- -Odontographic Journal. 



