412  The  Fixation  of  Sulphide. 
As  an  arbitrary  standard,  consider  the  standard  Caramel  as  one 
of  which  o.oi  gramme  (represented  by  lo  c.c.  of  the  diluted  solu- 
tion made  up  to  50  c.c.  with  water)  is  required  to  match  50  c.c. 
of  the  color  standard.  Call  this  standard  Caramel  100  per  cent. 
Caramel  as  found  on  the  market  will  usually  test  around  this  figure. 
To  obtain  the  Colorimetric  value  of  any  other  Caramel  divide 
100  X  10  by  the  number  of  c.c.  of  the  diluted  Caramel  Solution 
required.  For  example,  in  a  particular  test,  20  c.c.  of  the  solution 
of  the  sample  of  Caramel  were  required  to  match  the  color  standard. 
Then  the  Colorimetric  value  of  the  Caramel  sample  equals  ^-^^  ^-  = 
50  per  cent.  In  other  words,  this  particular  sample  was  one-half 
strength.    This  strength  is  a  convenient  one  for  making  elixirs. 
Among  the  advantages  of  this  method  I  might  mention  that 
the  tints  of  the  Ammonia  Solution  and  diluted  Caramel  Solution 
are  practically  identical.  The  materials  for  making  the  test  are  to 
be  found  in  every  laboratory  and  the  apparatus  required  consists 
simply  of  a  burette,  pipettes,  and  two  Nessler  glasses.  The  two 
vials  of  liquid  before  you  show  how  similar  these  solutions  are  in 
tint  and  illustrate  the  practicability  of  the  method.  This  method 
is  particularly  valuable  from  the  fact  that  it  enables  the  operator 
to  give  a  numerical  value  to  any  given  sample  of  Caramel,  a  point 
of  importance  in  making  purchases,  as  well  as  in  the  manufacturing 
laboratory. 
Laboratory  of  Noyes  Bros.  &  Cutler,  Saint  Paul,  Minn. 
THE  FIXATION  OF  SULPHIDE  BY  BASIC  BISMUTH 
COMPOUNDS. 
By  J.  L.  Stingel, 
From  the  Cleveland  School  o'f  Pharmacy,  Cleveland,  O. 
In  a  letter  to  the  /.  A.  M.  A.  (July  16,  1910,  Vol.  55,  p.  236), 
Dr.  Hulse  describes  his  experience  with  the  so-called  creams,  milks 
or  magmas  of  bismuth,  in  the  treatment  of  infantile  disorders,  par- 
ticularly calling  attention  to  the  fact  that  the  characteristic  brown 
or  black  color  of  the  stools  was  absent. 
At  the  suggestion  of  Prof.  Sollmann,  of  the  Western  Reserve 
University  Medical  College,  the  writer  made  a  number  of  experi- 
