STUDENTS HISTOLOGY 



PART FIRST 

 TECHNOLOGY 



THE LABORATORY MICROSCOPE 



The histologist should be provided with a microscope, in which 

 the principal features of the laboratory instrument, Fig. 1, are 

 embraced. 



The body A, which carries the optical parts, is made of two 

 pieces of brass tubing, one sliding within the other and providing 

 for alterations in length. The objectives, B, C, D, are attached to 

 the body by means of the triple nose-piece, E. The nose-piece 

 is so pivoted that either objective may be turned into the optical 

 axis at will. The eye-piece, F, slips into the upper part of the 

 body with but little friction, so that it may be quickly and 

 easily removed. 



The coarse or quick adjustment for focusing consists of a rack, 

 G, which is attached to the body, and into this gears a small 

 (concealed) pinion turned by the milled heads, H. 



The more delicate adjustments are accomplished by means of a 

 micrometer screw acting by a simple mechanical device upon an 

 enclosed spring in connection with a prism slide. By turning the 

 milled head, L, the body of the instrument is raised or lowered, as 

 desired, and with extreme delicacy. 



The stage, M, upon which objects are placed for examination, 

 is perforated, and an iris diaphragm and Abbe condenser, K, may 

 be inserted. The iris diaphragm enables one to alter the size of 

 the opening at will. Below the stage an arm may be seen which 

 carries a sliding fork supporting the mirror, N, one side of which 

 is plane and the other concave. 



