CONTENTS. 



CHAPTER I. 



MODERN INVENTIONS, AND THEIR RESULTS. 



SECT. PAGE 



1. The Steam-Engine, Electric Telegraph, 1 



2. The Telescope, 3 



3. The Microscope, . . , . . . ' . . . . 4 



4. Chalmers on the Telescope and Microscope, .... 5 



5. Imperfections, and their Removal, 7 



6. Compound Achromatic Microscope, 10 



7. Early Forms of the Microscope, 11 



8. Recent Improvements, . . ..-.- . . . 14 



9. Future Capabilities, . < r 16 



CHAPTER II. 



EARLY DISCOVERIES BY THE MICROSCOPE. 



1. Extent of Field, 19 



2. Difficulty of Selection, . . .... . . 20 



8. Trembley's Researches, The Hydra, , . . 21 



4. Ehrenberg's Discoveries, 24 



5. Classification : Vegetables or Animals ? 25 



6. Berlin, ...,. 28 



7. Extension of Microscopic Discoveries, 29 



8. Minuteness of Organic Remains, 31 



9. Agencies in Creation, 32 



CHAPTER III. 



MICROSCOPIC VEGETABLES. 



1. Extension of the Botanical Field, 36 



2. Desmidieae, Diatomaceae, &c., 36 



3. Their abundance, 38 



4. Their uses, 39 



5. Volvocinese, 41 



6. Monas Crepusculum, ....;.... 43 



