TABLE OF CONTENTS. XI 



CHAPTER II. DEVELOPMENT IN DIFFERENT MEDIA. 



PAGE 



1. ROLE OF BACTERIA IN FERMENTATIONS .... 137 



Acetic Fermentation 139 



Arnmoniacal Fermentation 142 



Lactic and Butyric Fermentation 144 



2. ROLE IN PUTREFACTION AND NITRIFICATION . . 148 



PART THIRD. 



TECHNOLOGY. 



1. METHODS OF CULTIVATION 156 



Methods of obtaining Pure Stock 156 



Natural Culture-Fluids 161 



Blood 161 



Milk* 163 



Urine 164 



Aqueous Humor 165 



Artificial Culture-Fluids 167 



Sterilization of Culture-Fluids 168 



Culture Tubes and Flasks 171 



Culture Flasks used by the Author 175 



Culture Oven 180 



Thermostat for Gas 181 



2. THE RECOGNITION OF BACTERIA 184 



3. STAINING BACTERIA 186 



Staining the Tubercle Bacillus 190 



Baumgarten's Method 191 



Ehrlich's Method 191 



Gibbs' Method 192 



4. PHOTOGRAPHING BACTERIA 194 



5. COLLECTION OF ATMOSPHERIC BACTERIA .... 197 



Examination of Water 201 



6. ATTENUATION OF VIRUS 201 



Method of Pasteur . . 202 



