AmAuJ.?if93arm'|  Abstracts  from  the  French  Journals.  385 
of  acid  found  the  weight  of  the  metal  is  ascertained.  In  the  estima- 
tion of  alkaloids  these  must  be  present  either  as  hydrochlorate  or 
as  sulphate  ;  the  former  salt  is  precipitated  with  silver  nitrate,  the 
latter  with  lead  nitrate ;  the  precipitates  obtained  are  suspended  in 
water,  decomposed  by  hydrogen  sulphide,  and  the  liberated  acid, 
corresponding  to  the  amount  of  alkaloid,  titrated  with  T^  alkali. — 
(Bollet.farmac),  Pharm.  Post,  1893,  297. 
Benzoin  constituents. — The  results  of  an  analysis  of  Sumatra 
benzoin  concluded  shortly  after  the  appearance  of  the  analysis  by 
F.  Llidy  {Am.  Journ.  Pharm.,  1893,  223)  are  briefly  stated:  (1) 
The  benzoic  acid  occurring  in  this  variety  is  free,  while  the  cinnamic 
acid  is  combined  as  salts  of  benzoresinol  and  resinotannol ;  (2) 
Styrol  is  uncombined  and  present  only  in  small  quantity ;  (3)  the 
chief  constituents  are  the  esters  of  benzoresinol  and  resinotannol,  the 
latter  being  in  larger  quantity ;  (4)  Sumatra  benzoin  is  completely 
soluble  in  ether  and  alcohol;  petroleum -ether  (boiling  point  400  C), 
and  petroleum-benzin  (boiling  point  65 0  C.)  dissolve  very  little; 
benzol  is  only  a  partial  solvent ;  (5)  vanillin  is  present  uncombined 
and  exists  in  quantity  of  less  than  1  per  cent.  Siam  benzoin  gave 
results  as  follows:  (1)  It  is  sparingly  dissolved  by  petroleum-ether 
and  petroleum-benzin ;  benzol  dissolves  about  90  per  cent., 
while  ether  and  alcohol  dissolve  it  completely ;  (2)  the  benzoic  acid 
(cinnamic  acid  was  not  found)  is  present  in  very  large  part,  as  the 
ester  of  benzoresinol  and  resinotannol,  in  small  quantity  it  is  present 
in  the  free  state ;  (3)  the  chief  constituents  are  again  the  benzoic 
esters  of  benzoresinol  and  resinotannol,  the  latter  predominating  ; 
(4)  vanillin  is  present  uncombined  to  the  extent  of  1-5  per  cent.;  (5) 
benzyl-benzoate  was  not  detected. — J.  Salkind  (Dorpat  Dissert^), 
Pharm.  Post,  1893,  330. 
ABSTRACTS  FROM  THE  FRENCH  JOURNALS. 
Translated  for  The  American  Journal  of  Pharmacy. 
A  process  for  the  volumetric  estimation  of  mercury  based  upon  the 
reaction  of  a  mercuric  salt  with  protochloride  of  tin  is  published  by 
M.  J.  Laborde  (Jour,  de  Pharm.  et  de  Chim.,  May,  1893,  p.  507). 
For  obtaining  the  protochloride  solution,  8  gm.  of  tin  are  dissolved 
in  100  cc.  hot  hydrochloric  acid  and  diluted  to  2  litres.  Ordinary 
precautions  must  be  taken  to  preserve  it  as  far  as  possible  from  the 
