1690 



Journal of Applied Microscopy 



as the typhoid bacillus, but it is safe to say that if either is present in drinking 

 water it should be boiled before using. 





^Sm^ 





* i 



t / H, < 





Fig. VII. Bacillus coli communis, culture. Stained 

 with Loeffler's Alkaline Blue. Magnified 1200 diam- 

 eters, Bausch & L(imb ^5 oil immersion objective. 

 Compensating Photo ocular No. 2. 





Fig. VIII Gciiim iuu^. (.i\xr slip prepared direct 

 from the pus. Methyl violet stain. Magnified 1400 

 diameters, Bausch i*i Lomh ,'2 oil immersion ob- 

 jective. Compensating Photo ocular. 



GONOCOCCUS. 



The preparation of mounted slides of this bacterium is easy and simple. To 

 examine Gonococcus spread a thin layer of the fresh pus on a clean cover-glass, 

 held in a Cornet forceps, using the inoculating needle. Pass the cover through 

 the flame three times, film side up, and use any of the anilin stains according to 

 formulae given. Beautiful crisp staining may be obtained with methyl violet, 

 with the advantage that if the preparation is over-stained any amount may be 

 washed out with alcohol and its action immediately stopped by applying water. 

 The bacteria will be found in pairs, located in or on the pus cells. In appear- 

 ance they are like two biscuits, with the fiat sides toward each other, and 

 separated by a minute distance usually equal to about half the diameter of the 

 bacteria. William H. Knap. 



Harvey Medical College. 



The Technique of Biological Projection and Anesthesia of 



Animals. 



Copyrighted. 



Biological projection, as used in this series of articles, includes all the work 

 with stereopticons, projection microscopes, and their modifications, using solar, 

 electric, or oxyhydrogen lights, by which live plants and animals are exhibited 

 as living charts on a screen. The illustration gives an example of the work 

 done with lenses of low or medium power. The objective used was a Leitz No. 

 3, distance from projection microscope to screen thirty feet, magnification 650 

 diameters. The study of small live animals and plants under the hand lens, or 

 compound microscope, is incomparably more valuable than the study, even for 

 greater lengths of time, of the best pictures and diagrams, useful as these are in 

 their place. Wall charts, lantern slides, models, and other devices have filled a 



