CHAPTER V 



DRAWING WITH THE MICROSCOPE 



APPARATUS AND MATERIAL FOR THIS CHAPTER 



Microscope, Abbe and Wollaston's camera lucidas, drawing board, thumb 

 tacks, pencils, paper, and microscope screen, (Fig. 66), microscopic prepara- 

 tions. 



DRAWING MICROSCOPIC OBJECTS 



§ 198. Microscopic objects may be drawn free-hand directly 

 from the microscope, but in this way a picture giving only the gen- 

 eral appearance and relations of parts is obtained. For pictures 

 which shall have all the parts of the object in true proportions and 

 relations, it is necessary to obtain an exact outline of the image of 

 the object, and to locate in this outline all the principal details of 

 structure. It is then possible to complete the picture free-hand 

 from the appearance of the object under the microscope. The ap- 

 pliance used in obtaining outlines, etc. , of the microscope image is 

 known as a camera lucida. 



§ 199. Camera Lucida. — This is an optical apparatus for en- 

 abling one to see objects in greatly different situations, as if in one 

 field of vision, and with the same eye. In other words it is an opti- 

 cal device for superimposing or combining two fields of view in one 

 eye. 



As applied to the microscope, it causes the magnified virtual 

 image of the object under the microscope to appear as if projected 

 upon the table or drawing board, where it is visible with the draw- 

 ing paper, pencil, dividers, etc., by the same eye, and in the same 

 field of vision. The microscopic image appears like a picture on the 

 drawing paper (see note to § 202). This is accomplished in two 

 distinct ways: 



(A) By a camera lucida reflecting the rays from the microscope 

 so that their direction when they reach the eye coincides with that 



