ANoveTber,hi8r99m-}      Valuation  of  Drugs  and  Foods.  539 
separating  funnel.  To  the  filtered  liquid  5  c.c.  of  a  dilute  H2S04  (0-5 
per  cent.)  solution  are  added.  The  aqueous  solution  containing  the 
alkaloids  is  separated.  If  this  solution  does  not  clear  rapidly  another 
portion  of  ether,  after  its  separation,  may  be  added,  when  the  re- 
maining oil  is  removed.  (1)  A  drop  of  this  solution  is  placed  on  a 
watch-crystal  with  a  drop  of  dilute  ammonia  water  and  then  evapor- 
ated on  a  water-bath,  giving  a  residue  which  is  colored  green  immedi- 
ately with  HaS04.  The  green  color  is  soon  replaced  by  a  brown  colora- 
tion. Using  two  drops  of  the  alkaloidal  solution  instead  of  one,  a  more 
marked  and  permanent  green  coloration  is  produced  with  H2S04  (2) 
Mayer's  reagent  produces  a  slight  white  precipitate  with  a  drop  of 
the  solution  containing  the  alkaloid.  (3)  Tannin  solution  also  gives 
readily  a  slight  yellow  precipitate..  (4)  I  -f  KI  solution  produces 
an  orange-brown  precipitate. 
(h)  Cinchona  Flava  (containing  7  per  cent,  of  total  alkaloids,  of 
which  3  per  cent,  is  quinine). — One  gramme  of  the  powder  is 
macerated  over  night  with  10  c.c.  of  a  modified  Prollius  solution. 
The  solution  is  filtered  into  a  small  separating  funnel  and  5  c.c.  of  a 
dilute  H2S04  (0*5  per  cent.)  solution  are  added.  After  agitation  and 
allowing  to  stand  until  the  two  liquids  separate,  the  aqueous  solution 
containing  the  alkaloids  is  separated.  This  solution,  which  is  slightly 
fluorescent,  is  rendered  neutral  with  dilute  ammonia  water,  and  one 
drop  contains  about  0-00015  gramme  of  quinine.  (1)  One  drop  of 
this  solution  is  mixed  with  nine  drops  of  water,  and  upon  the  addition 
of  a  drop  of  bromine  water,  followed  by  an  excess  of  NH4OH  the 
thalleioquin  reaction  readily  takes  place.  (2)  If  one  drop  of  the  neu- 
tral solution  be  mixed  with  four  drops  of  water  and  a  drop  of  bro- 
mine water,  followed  by  a  drop  of  a  solution  of  ferrocyanide  of  potas- 
sium, and  then  an  excess  of  NH4OH,  a  red  coloration  is  immediately 
produced,  which  disappears  shortly. 
II.  PHYSICAL  TESTS. 
There  are  certain  physical  tests  which  are  no  doubt  of  consider- 
able value  and  which  may  be  readily  applied  with  very  little  cost. 
(A)  In  examining  the  galls  (Aleppo)  upon  the  market  one  finds  a 
varying  number  from  which  the  insect  has  emerged  and  others 
in  which  the  grub  or  winged  insect  varies  in  the  degree  of  develop- 
ment. In  all  of  the  cases  where  we  have  galls  with  a  more  or  less 
empty  central  chamber,  we  find  that  they  are  rather  light  and  not  so 
