sep0™;  fa™- }  Reactions  of  Saponin.  393; 
certainly  to  the  advantage  of  the  truly  medicinal  principles,  the  solu- 
tion and  preservation  of  which  is  the  object  of  that  class  of  prepara- 
tions denominated  tinctures.  We  believe  that  the  alcohol  in  the 
tinctures  of  the  U.  S.  Pharmacopoeia  is  weaker  than  that  ordered  by 
any  other  pharmacopoeia,  and  that  fact  alone  should  invite  to  com- 
parative experiments,  not  with  the  view  of  ascertaining  the  amounfc 
of  extract  dissolved,  but  to  determine  the  percentage  of  the  definite 
active  principles  taken  up  by  the  different  menstrua.] 
REACTIONS  OF  SAPONIN* 
By  Dr.  Hermann  Koehler. 
1.  Saponin  yields  with  water  an  opalescent  solution,  foaming  like 
soap  solution  ;  it  is  insoluble  in  ether,  but  soluble  in  petroleum  ether, 
benzin,  chloroform,  alcohol  and  amylic  alcohol. 
2.  Concentrated  sulphuric  acid  yields  with  it  a  carmine  red,  faintly 
brownish  solution,  which  becomes  violet  blue  on  the  margin  after 
about  fifteen  minutes. 
3.  The  addition  of  bichromate  of  potassium  changes  this  color  to 
dirty  green. 
4.  Saponin  dissolves  readily  and  completely  in  diluted  and  concen- 
trated nitric  acid  with  a  yellow  color. 
5.  The  addition  of  bichromate  to  this  solution  produces  no  change. 
6.  On  boiling  saponin  with  concentrated  phosphoric  acid,  a  charac- 
teristic odor  or  coloration  is  not  produced. 
7.  Bichromate,  added  after  the  phosphoric  acid,  produces  no 
change. 
8.  Evaporated  with  muriatic  acid,  saponin  yields  a  gray  jelly;  bi- 
chromate merely  darkens  the  liquid. 
9.  Saponin  gives  with  acetic  acid,  with  difficulty,  a  colorless  solu- 
tion, in  which  no  change  is  produced  by  bichromate. 
10.  Saponin  is  split,  like  other  glucosides,  by  dilute  acids. 
11.  Ammonia  water  dissolves  saponin  in  the  cold,  yielding  a  foam- 
ing solution,  from  which  acetic  acid  reprecipitates  saponin. 
12.  Caustic  soda  dissolves  saponin,  but  the  solution  is  less  clear 
and  foams  like  soap  solution.    Acetic  acid  reprecipitates  it. 
13.  Potassa  behaves  precisely  like  ammonia  and  soda. 
*  Die  lokale  Anaesthesirung  durch  Saponin  ;  Halle,  1873.  Translated  from- 
Neues  Jahrbuch  fur  Pharmacie,  1873,  June. 
