PHARMACY  OF  THE  CINCHONAS. 
403 
the  dried  extract  are  in  the  same  direction,  and  here  the  chances 
of  error  and  inaccuracy  are  somewhat  diminished,  whilst  the  ex- 
periments for  extract  were  more  numerous,  though  the  difference 
in  the  proportion  was  often  smaller  than  in  these  two  percola- 
tions. Here  the  difference  is  208  grs.,  or  nearly  12*7  per  cent, 
of  the  whole  extract  in  favor  of  alcohol  as  a  menstruum.  The 
dry  extract  by  alcohol  is  of  a  richer  darker  color,  and  makes  a 
heavier  denser  powder.  The  powdered  extracts,  when  subjected 
to  the  solvent  action  of  Alcohol,  Diluted  Alcohol,  and  Acidulated 
Water,  in  the  cold,  dissolve  in  the  following  proportion  : 
Of  the  Alcoholic  extract,  85*8  p.  c.  is  soluble  in  Cold  Alcohol. 
78-8       "  "     Diluted  Alcohol. 
49-7       "  "     Acidulat.  Water. 
Of  the  extract  by  Dil.  Alcohol,  85-4  "  "      Cold  Alcohol. 
87-8  "  "     Diluted  Alcohol. 
51-7"  "     Acidulat.  Water. 
But  the  amount  of  extract  yielded  to  Alcohol  being  12-7  per 
cent,  greater — or,  by  concession  to  the  diluted  menstruum,  in 
order  to  avoid  all  probable  sources  of  error,  say  only  5  per  cent, 
greater, — then  the  proportion  of  total  extract  soluble  again  would 
stand  as  follows : 
Alcoholic  Extract.  Extract  from  Dil.  Alcohol. 
By  Alcohol,  00-09  p.  c.  85-40 
Dil.  Alcohol,  82-74  "  87-80 
Acid.  Water,        52-18    "  51-70 
Total  redissolved,  225-01  224-9 
Or,  would  be  practically  the  same  in  weight.  The  residue  left 
undissolved  by  these  menstrua  is,  however,  very  different  in  ap- 
pearance from  the  two  extracts.  The  portion  of  the  alcoholic 
extract  insoluble  in  alcohol  is  pulverulent,  tasteless,  and  insoluble 
in  water.  The  corresponding  portion  from  the  extract  by  Dilu- 
ted Alcohol  is  compact,  of  a  gummy  fracture,  slightly  bitter 
and  saline  in  taste,  waxy  between  the  teeth,  and  soluble  in  water 
to  a  considerable  extent.  The  insoluble  residues  left  by  Diluted 
Alcohol  were  similar  in  appearance  and  taste,  and  in  solubility, 
though  very  unlike  in  quantity.  That  of  the  extract  from  Dilu- 
ted Alcohol  is  much  smaller  in  quantity,  and  more  waxy  between 
