CONTENTS. xiii 



CHAPTER VI. 



INVESTIGATIONS ON THE "DISEASES" OF BEER, 

 PRODUCED BY ALCOHOLIC FERMENTS. 



PAGE 



1. INTRODUCTION 156 



2. HOW THE DOCTRINE OF " DISEASES " IN FERMENTED LIQUIDS 



WAS GRADUALLY DEVELOPED 157 



Needham's and Spallanzani's investigations on spontaneous genera- 

 tion 158 



Scheele discovers the method of preserving vinegar by heat .. 158 

 Chaptal and the first indication of the relationship of the diseases 



of wine and micro-organisms .. .. .. .. .. 159 



The method of heating is further developed by Appert, and is 



employed also for the preservation of wine and beer .. .. 159 



Franz Schulze, Theodor Schwann and Cagniard Latour .. .. 162 



Kutzing discovers an acetic acid bacterium .. 163 



Turpin's theory of fermentation .. .. .. .. .. 164 



Schroder and Dusch's cotton- wool filters for sterilising air .. .. 164 



Bail 165 



Pasteur's investigations on lactic fermentation and spontaneous 



generation .. .. .. .. .. .. .. .. 166 



On acetic fermentation 167 



On wine 169 



Reess 169 



Holzner's, Lintner's and Engel's publications on Sacch. exiguus .. 170 



Cohn, Cienkowski, Harz 171 



Pasteur's * Etudes sur la biere ' 172 



Lintner, sen., on "light yeast" .. .. .. .. .. 177 



Nageli 178 



Discussions on the degeneration and transformation of brewery yeast 179 



The standpoint of the French school in 1883 181 



Koch's school .. .. .. .. .. .. .. .. 182 



Fitz, Thausing 182 



3. MY INVESTIGATIONS 184 



Problem and Method .. .. .. .. .. .. .. .. 184 



Yeast Turbidity in Beer caused by Sacch. ellipsoideus II. and Sacch. 



Pastorianus HI, 188 



Main result ,. .. .. .. .. .. .. .. 200 



Saccharomyces exiguus .. .. .. ., .. .. .. 201 



Main result . . . . . . . . . . . . . . . . 204 



Disagreeable Odour and Taste produced in Beer by Sacch. Pastorianus I. 205 



Main result .. .. .. .. .. .. .. .. 210 



Literature from 1883 to the present day 213 



