500  Abstracts  from  the  French  Journals.  {Am •^i£a.arra' 
from  at  least  two  hundred  times  its  weight  of  water  by  sodium  car- 
bonate it  is  easily  held  in  suspension  in  syrup,  its  properties  being 
thus  preserved  indefinitely. — Bull,  de  pharm.  de  Bord.,  July,  1893, 
p.  207. 
Citrate  of  caffeine,  according  to  M.  Soucheire  {Rep.  de  Pharm  ), 
does  not  exist  in  aqueous  solution.  He  prepared  the  salt  by  dissolv- 
ing i-8o  gm.  caffeine  in  30  cc.  pure  chloroform,  and  r8o  gm.  citric 
acid  in  15  cc.  absolute  alcohol,  mixing  the  two  solutions  and  evap- 
orating on  a  water-bath ;  the  product  was  a  white  crystalline  pow- 
der, insoluble  in  chloroform,  but  soluble  in  two  parts  of  chloroform 
and  one  part  alcohol.  The  solution  of  the  salt  in  water  was 
evaporated  on  a  water-bath,  and  the  residue  treated  with  chloroform, 
which  took  up  caffeine  and  left  citric  acid  as  a  residue,  proving  that 
the  water  had  split  up  the  caffeine  citrate  into  a  simple  mixture  of 
caffeine  and  citric  acid. 
Effervescent  ferric  lactate. — Cesaris  gives  the  following  formula  in 
Boll.  farm:.  Ferric  lactate  20  parts,  citric  acid  40  parts,  bicarbonate 
of  soda  80  parts,  and  white  sugar  30  parts.  The  pulverized  sub- 
stances are  mixed,  and  submitted  to  the  heat  of  a  water-bath  in  a 
porcelain  capsule ;  then  agitated  constantly  until  a  granular  mass  is 
obtained. — Jour,  de  pharm.  d'Anvers,  August,  1893,  p.  309. 
Kelene  is  a  new  name  for  ethyl  chloride,  which  renders  efficacious 
service  in  minor  surgery. — Jour,  de  pharm.  d'Anvers,  July,  1893,  P- 
260. 
Sensitive  tincture  of  litmus  is  prepared  according  to  Boll.  chim. 
farm.,  1893,  P-  29^  (through  Rep.  de  pharm.,  July,  1893,  p.  319)  by 
exhausting  the  litmus  with  hot  distilled  water,  evaporating  the 
filtered  solution,  saturating  with  acetic  acid,  and  again  evaporating 
to  thick  extract  consistence.  This  is  now  placed  in  a  flask  and  90  per 
cent,  alcohol  added.  The  blue  coloring  matter  is  precipitated,  while 
the  red  substance  and  the  acetic  acid  remain  in  solution.  Filter ; 
wash  with  alcohol ;  dissolve  the  coloring  matter  in  hot  water  and 
again  filter.  The  tincture  should  be  preserved  in  flasks  stoppered 
with  cotton. 
The  filtration  of  pepsin  solutions  is  facilitated  by  the  addition  of 
sugar  of  milk,  which  exerts  merely  a  mechanical  action  and  causes 
the  liquid  to  remain  limpid. — Wearn,  in  Gior.  di  farm,  et  di  chim., 
June,  1893,  through  Rep.  pharm.,  July,  1893,  P-  32°- 
Concentrated  solution  of  salicylic  acid  is  prepared  by  M.  Jaudon 
