1896.] 



MICROSCOPICAL JOURNAL. 



206 



the microscope. The observer accurately centres the mi- 

 crometer rulings, then removes the eyepiece and projects 

 the image of the micrometer rulings on the camera 

 screen. The microscope is then moved to such position 

 that the centre of the projected micrometer image is 

 exactly in the centre of the screen. This position of the 

 microscope is marked once for all, and whenever after- 

 ward the microscope is placed in the same position the 



Fig. 7. — Typhoid bacillus, grown on glycerin agar, stained with carbol fuch- 

 siu. X 1000 diameters. Ex^wsed two minutes to oil light, using Bausch 

 & Lomb 1-12-inch oil-immersion objectives, amplifier in draw tulie, 

 and Bausch & Lomb 1-5-inch objective in substage. 



By courtesy of Medical Record. 



centre of the object will be projected on the centre of 

 the screen. The position of the lantern directly in front 

 of the microscope should also be marked. 



Adjustment of the Light. — Proper adjustment of the 

 light is very important in working with artificial light, 

 for upon this its eflBciency depends. It must be properly 

 placed relative to the lantern condensers and the light 

 from them must be properly concentrated upon the ob- 



