ATaSary  Pi899.ir ' }    Recen  t  L  iterative  Re  la  ting  to  Pharmacy.  3  7 
It  clears  on  warming  and  crystallizes  on  cooling. 
A  hydrochloric  acid  solution  when  treated  with  bromine  water, 
and  the  excess  of  bromine  driven  off,  becomes  blue  on  addition  ot 
a  trace  of  ferrous  sulphate  solution  (10  per  cent.)  and  a  few 
drops  of  ammonia  water.    Caffeine  shows  this  reaction,  however. 
Acicular  dark  green  crystals  of  theobromine  tetraiodide  are 
formed  when  the  alkaloid,  dissolved  in  hydrochloric  acid,  is  treated 
with  normal  iodine  solution,  the  precipitate  separated  from  the 
supernatant  liquid,  redissolved  in  potassium  iodide  solution  (10  per 
cent.)  and  allowed  to  crystallize. 
He  gives  as  the  most  important  test  the  scant  solubility  of  theo- 
bromine in  95  per  cent,  alcohol.  The  most  saturated  alcoholic  solu- 
tion, even  after  agitation  for  forty-eight  hours  at  21°  C,  contains 
only  o  0045  grammes  in  10  c  c. ;  while  caffeine,  the  most  likely  adul- 
terant, will  dissolve  at  21 0  C.  in  proportion  of  0.093  gramme  to  10 
c.c. 
This  slight  alcoholic  solubility  will  detect  the  presence  of  almost 
all  other  organic  adulterants,  save  starch ;  such  sophistications 
being  usually  quite  soluble  in  alcohol.  Starch  is  detected  by  its 
insolubility  in  cold  diluted  hydrochloric  acid  ;  inorganic  matter  by 
its  ash.  H.  V.  A. 
TESTING  SODIUM  BICARBONATE. 
Skubich  (Apoth.  Zeit ,  1898,  644)  reports  trials  of  the  various 
methods  of  detecting  sodium  carbonate  in  the  bicarbonate. 
He  finds  Kublis'  test — the  cloudiness  produced  when  a  quinine 
solution  is  added  to  bicarbonate  solution,  that  contains  carbonate  
is  unsatisfactory;  as  is  also  Ley's  test;  the  turbidity  produced  in  a 
solution  of  bicarbonate  containing  carbonate. 
On  the  other  hand  he  approves  the  test  of  the  German  Pharma- 
copoeia— the  absence  of  red  tint,  when  phenolphtalein  is  added  to 
a  solution  of  1  gramme  bicarbonate  in  20  c.c.  water,  to  which  has 
been  added  0-2  c.c.  normal  acid. 
As  precautions,  however,  he  notes  that  some  new  glassware  is 
sufficiently  alkaline  to  redden  phenolphtalein,  and  this  factor  must 
be  eliminated ;  that  temperature  affects  color,  solutions  decidedly 
red  at  300  C.  being  colorless  at  -o°  C. 
Taking  absolute  bicarbonate  and  adding  thereto  definite  quanti- 
ties of  carbonate  solution,  he  establishes  the  approximate  value  of 
