BACTERIOLOGICAL APPARATUS 



53 



Apparatus for the study of bacteria. As bacteria are 

 very small, it is necessary in order to study their morphology 

 to have a compound microscope with a sub-stage condenser, 



THE MICROSCOPE IN SECTION. 



1. Positive ocular. 



2. l)raw-tube. 



3. Main tube or body. 

 4-5. Society screws in the 



draw-tube and body. 



6 Objective in position 



7 Stage. 



8 Spring for holding 



slides. 



9 Sub-stage condenser. 

 10 Iris diaphragm. 



11. Plane and concave mir- 



ror. 



12. Horse-shoe base. 



13. Rack a nd pinion for con- 



denser. 



14. Flexible pillar. 



15. Spiral spring of fine 



adjustment.- 



16. Fine adjustment. 



17. Coarse adjustment. 



From Gage, the Microscope and Microscopical Methods, 

 Fig. 12. A compound microscope. 



oil immersion objective and suitable eye-pieces. There are 

 many accessories that are often very desirable and occasion- 

 ally necessary. The accompanying diagram illustrates a 

 microscope suitable for this purpose, showing the essential 

 parts. 



