1892.] 



MICROSCOriCAL JOURNAL. 



85 



For Color Images. — Use some stained microbes, as Bacillus 

 tuberculosis for object. Put a drop of the immersion liquid on 



-% . ,n 



Explanation of Plate II. 



Fig. 23. Showing the method of mounting 

 letters in stairs to show the order of coming 

 into focus. 



a, b, c, d. The various letters indicated by 

 the oblique row of black marks i n the sectional 

 view. 



Slide. The glass slide on which the letters 

 are mounted. 



Fig. 24. Glass rod showing the appearance 

 in air (a), and in 50 per cent, glj'cerine (b). 



Fig. 25. Glass rod coated with collodion to 

 show double contour. At the left the collo- 

 dion is represented as collecting iu a drop. 



Fig. 26. Mammalian blood-corpuscles on 

 edge to show a surface view (a) and an optical 

 section (b). 



Fig. 27. WoUaston's Camera Lucida, 

 showing the rays from the microscope and 

 Irom the drawing surface, and the position of 

 the pupil of the eye. 



Axis, Axis. A.xial rays from the microscope 

 and from the drawing surface. 



Camera lucida. A section of the quad- 

 rangular prism showing the course of the rays 

 in the prism from the microscope to the eye. 

 As the rays are twice reflected, they have the 

 same relation on entering the eye that they 

 would have by looking directly into the 

 ocular. 



A B. .The lateral rays from the microscope 

 and their projection on the drawing surface. 



C D. Rays from the drawing surface to the 

 eye. 



A D, A' D'. Overlapping portion of the two 

 fields, where both the microscopic image and 

 the drawing surface, pencil, etc , may both be 

 seen. It is represented i.y the shaded part in 

 the overlapping circles at the right. 



Ocular. The ocular of the microscope. 



P. The drawing pencil. Its point is shown 

 in the overlapping fields. 



Fig. 28." Figure showing the position of the 

 microscope, the camera lucida, and the eye, 

 and the different sizes ot the image depending 



