THE  AMEKICAN 
JOURNAL  OF  PHARMACY 
SEPTEMBER,  ipio 
- 
A  NOTE  ON  THE  ASSAY  OF  THE  HALOGEN  COM- 
POUNDS OF  THE  U.  S.  PHARMACOPCEIA,  WITH 
SPECIAL  REFERENCE  TO  THYMOL  IODIDE. 
By  Elias  Elvove. 
In  connection  with  an  investigation  on  the  relative  bactericidal 
value  of  the  various  embalming-  fluids  on  the  market,  which  is 
now  in  progress  in  the  Division  of  Pathology  and  Bacteriology  of 
the  Hygienic  Laboratory,  it  was  required,  among  other  things,  to 
examine  a  number  of  these  fluids  for  the  presence  of  chloral  and 
to  estimate  its  quantity  wherever  found.  Owing  to  the  more  or 
less  complex  nature  of  these  fluids  and  especially  to  the  fact  that 
nearly  all  of  them  contain  comparatively  large  amounts  of  for- 
maldehyde, the  methods  for  estimating  chloral,  such  as  those  given 
by  Allen,  Holland,  or  Schimpf,  are  inapplicable  to  these  fluids. 
Thus  Allen  1  gives  the  processes  of  Miiller,2  Wood,3  and  Meyer,4 
all  of  which  depend  on  the  reaction  of  chloral  with  alkalies  with 
the  separation  of  chloroform  and  measuring  the  volume  of  the 
latter.  The  smallest  of  the  quantities  of  chloral  operated  on  is 
i  or  2  grammes  (Meyer),  while  in  the  method  of  Wood  10  grammes 
are  used,  and  in  the  method  of  Miiller  25  grammes.  In  cases 
such  as  the  embalming  fluids  under  consideration,  where  we  may 
be  dealing  with  comparatively  small  quantities  of  chloral,  this 
circumstance  alone  would  bar  consideration  of  any  method  which 
1  Allen:   Commercial  Organic  Analysis,  3rd  e<±,  Vol  1,  pp.  229-230. 
2  Zeit.  f.  Chem.,  (2),  7,  66,  and  Jour.  Client.  Soc.,  24,  444. 
3  P 'harm.  Jour.,  (3),  1,  703. 
4  Meyer  (and  Haffter)  :  Ber.,  6,  600-601.  and  Jour.  Chem.  Soc,  26,  1163. 
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