XVlii CONTENTS. 



§ 16. Suspended Particles in Air and Water ; their relation to 

 Baeteria ... 



§ 17. Eecent Experiments on Heterogenesis . 



§ 18. Experiments with Filtered Air 



§ 19. Experiments with Calcined Air .... 



§ 20. Infusions withdrawn from Air 



§ 21. The Germ Theory of Contagions Disease 



§ 22. Experiments with Hermetically-sealed Vessels . 



§ 23. Conditions as to the Temperature and Strength of In- 

 fusions 



§ 24. Developmental Power of Infusions and Solutions : Air- 

 germs contrasted with Water-germs 



§ 25. Diffusion of Germs in the Air 



§ 26. Tray of one hundred Tubes .... 



§ 27. Some Experiments of Pastewr and their Relation to Bac- 

 terial Clouds ....... 



Note I. Action of Bacteria upon a Beam of Light 

 Note II. Fluorescence of Infusions . 



75 

 84 

 85 

 88 

 90 

 91 

 94 



98 



101 

 107 

 110 



121 

 127 

 128 



FURTHER RESEARCHES ON THE DEPORTMENT AND 

 VITALITY OF PUTREFACTIVE ORGANISMS. 



§ 1. Introduction 131 



§ 2. Experiments of Pasteur, Boberts and Cohn . . . 135 

 § 3. Hay-Infusions. Preliminary Experiments with Pipette- 

 bulbs 138 



§ 4. Hay- Infusions. Experiments with Cohn's Tubes . . 144 



§ 5. Hay-Infusions (in Closed Chambers) 146 



§ 6. Desiccation of Germs. New Hay and old . . . 148 

 § 7. Hay-Infusions. Further Experiments with Closed 



Chambers 150 



§ 8. Experiments with Soaked Hay ...... 154 



§ 9. Infusions of Fungi 158 



§ 10. Infusions of Cucumber, Beetroot, &c 161 



§ 11. New Experiments on Animal Infusions. Contradictory 



results 165 



§ 12. Infusions protected by Glass Shades containing Calcined 



Air 169 



§ 13. Further Precautions against Infection .... 171 



§ 14. Experiments in the Royal Gardens, Kew . . . . 174 



§ 15. Experiments on the Roof of the Royal Institution . . 177 

 § 16. Preliminary Experiments on the Resistance-limit of 



Germs to the temperature of Boiling Water . . 180 



