x CONTENTS 



PAGE 



Amygdalin *8i 



Dhurrin 182 



Phaseolunatin 182 



Lotusin 183 



Saponins 183 



General properties and uses 183 



Solubility 184 



Physiological action 185 



Chemistry 185 



Reactions 187 



Other glucosides 187 



Sinigrin 187 



Preparation . . . . . . ... . 187 



Coniferin 188 



Salicin 189 



Preparation 189 



Indicane .'......... 191 



Identification 191 



SECTION IV. TANNINS 193 



Occurrence 194 



Microchemical reactions 197 



Chemistry 200 



Pyrocatechol, catechol, or pyrocatechin 201 



Reactions 202 



Resorcinol 202 



Reactions 202 



Hydroquinone ........... 202 



Reactions 202 



Protocatechuic acid 203 



Reactions ........... 203 



Pyrogallol or pyrogallic acid 204 



Reactions 204 



Phloroglucinol 204 



Reactions 205 



Gallic acid 205 



Reactions 206 



Ellagic acid 206 



Reactions 207 



Phlobaphenes 208 



Tannins as glucosides 208 



Classification of tannins . . 209 



Properties and description of individual tannins ..... 211 

 Pyrogallol tannins . . . . . . . . .211 



Gallotannic acid 211 



Extraction ......... 213 



Reactions ........ . 214 



Detection of gallic acid in presence of gallotannic acid . 214 



Constitution 214 



Ellagitannic acid 216 



Pyrocatechol tannins 216 



Catechu tannic acid 216 



Catechin .......... 217 



Quercitannic acid . . S1 j 



Physiological significance of tannins ....... 217 



