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L57 



CONTENTS. 



THE MICROSCOPE. 



PAGE 



CHAP. I. 1. Origin of the term. 2. Simple microscopes are mag- 

 nifying glasses. 3. Compound microscope. 4. Object-glass and 

 eye-glass. 5. General description of the instrument. 6. Uses 

 of the field-glass. 7. Reflecting microscopes. 8. Conditions of 

 distinct vision in the microscope. 9. Effects of different mag 

 nifying powers. 10. Distinctness of delineation necessary. 11. 

 Hence aberration must be effaced. 12. Achromatic object- 

 lenses. 13. Sufficient illumination necessary. 14. Effects of 

 angular aperture. 15. Experiments of Dr. Goring. 16. Method 

 of determining the angular aperture. 17. Mutual chromatic and 

 spherical correction of the lenses 1 



CHAP. II. Mutual chromatic and spherical correction of the lenses 

 (continued). 18. Centering. 19. Compound object-pieces. 20. 

 The eye-piece. 21. Various magnifying powers adapted to the 

 same microscope. 22. Actual dimensions of the field of view. 23. 

 Means of moving and illuminating the object. 24. Focussing. 

 25. Preparation of the object. 26. General description of the 

 structure of a microscope. 27. The stage. 28. The illuminators. 

 29. The diaphragms 17 



CHAP. III. 30. Oblique plane reflectors. THE SUPPORT AND MOVE- 

 MENT OF THE OBJECT : 31. The stage. 32. Mechanism for focus- 

 sing. 33. Coarse adjustment. 34. Fine adjustment. 35. 

 Method of determining the relief of an object. 36. Difficulty of 

 bringing the object into the field. 37. Mechanism for that 

 purpose. 38. Mechanism to make the object revolve. 39. 

 Object to be successively viewed by increasing powers. 40. 

 Slides to be cleaned. 41. Compressor. 42. Apparatus for apply- 

 ing voltaic current. THE ILLUMINATION OP OBJECTS : 43. Curious 

 effects of light on objects. 44. Illumination by transmission 

 and reflection. 45. Microscopic objects generally translucent, or 

 iaay be made so. 46. Effects of varying thickness. 47. Varying 



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