Am.  Jour.  Pharin.") 
July,  189S.  / 
A  Species  of  Commelina. 
33* 
portions,  and  tested  for  alkaloids  with  Mayer's  reagent,  picric  acid, 
potassium  tri-icdide  and  phosphotungstic  acid.  All  of  these  reagents 
gave  small,  flocculent  precipitates,  but  they  may  have  been  due  to 
albuminous  matter,  and  not  to  alkaloids.  Another  special  search 
was  made  for  alkaloids  by  macerating  12  grammes  of  fresh  plant 
(dried)  with  alcohol  of  -820  specific  gravity  for  several  days.  The 
alcoholic  liquid  was  strained  off,  filtered  clear,  and  then  evaporated 
to  dryness  on  a  water-bath.  m  The  residue  was  treated  with  water 
previously  acidified  with  diluted  sulphuric  acid,  and  the  insoluble 
matter  separated  by  filtration.  The  filtrate  reacted  for  alkaloids  as 
follows :  phosphotungstic  acid  gave  a  large,  whitish  precipitate ; 
potassium  tri-iodide,  Mayer's  reagent  and  gold  chloride  gave  slight 
precipitates ;  picric  acid,  tannic  acid,  mercuric  chloride  and  platinic 
chloride  gave  no  precipitates. 
Fig.  7. 
The  existence  of  an  alkaloidal  substance  in  the  plant  is  an  un- 
settled matter,  as  the  tests  for  it  were  in  no  case  satisfactory,  partly 
because  of  the  very  small  amounts  of  the  substances  yielding  the 
tests  which  could  be  separated. 
Some  of  the  last-mentioned  filtrate  which  was  tested  for  alkaloids 
was  made  alkaline  with  potassium  hydrate  and  warmed  with  Feh- 
ling's  solution,  which  reagent  was  reduced.  An  exactly  equal  volume 
of  the  same  filtrate  was  boiled  with  some  diluted  sulphuric  acid,  then 
made  alkaline  and  treated  with  Fehling's  solution,  as  in  the  pre- 
ceding case,  when  an  increased  amount  of  cuprous  oxide  was  de- 
posited. While  this  action  is  not  taken  as  conclusive  evidence  of  a 
glucoside,  still,  considering  it  in  connection  with  behaviors  of  the 
same  character  noticed  in  the  proximate  analysis,  it  points  to  the 
