A^ug°usrt.^m"}      Potassium  Iodide  and  Bromide.  .383 
Sample  No.  7  showed  traces  of  sodium  and  sulphate.  It  did  not 
reach  the  standard  as  to  chloride. 
Sample  No.  8  contained  traces  of  sulphate  and  more  chloride  than 
the  standard  calls  for. 
Samples  Nos.  3  and  6  met  all  requirements  as  to  chloride. 
Sample  No.  1  conformed  to  all  requirements  of  the  Pharmacopoeia. 
Of  the  twelve  samples  of  potassium  iodide  examined,  two  only, 
both  from  the  same  firm,  met  all  pharmacopaeial  requirements. 
However,  it  should  be  mentioned  here  that  these  samples  were  of 
the  crystallized  salt.  The  firm  makes  no  granulated  potassium 
iodide. 
Of  the  eight  samples  of  potassium  bromide,  one  only  stood  all 
the  tests  of  the  Pharmacopoeia. 
The  answer,  therefore,  to  the  question  :  Potassium  iodide  and  bro- 
mide of  the  market — do  they  conform  to  the  requirements  of  the 
Pharmacopoeia  ?  must  be  answered  :  No  !  the  large  majority  do  not. 
CALCIUM  PHOSPHOGIAXERATE. 
This  compound  was  discovered  by  Pelouze,  who  prepared  the  acid  by  acting 
on  glycerin  with  anhydrous  phosphoric  acid.  Recently  Portes  and  Prunier 
{Jour,  de  Pharm.  et  de  Chun.,  [5]  29,  393)  have  prepared  the  acid  by  heating 
together  3  kilograms  of  60  per  cent,  liquid  phosphoric  acid  and  3*6  kilograms 
of  pure  glycerin,  at  no0  for  six  days.  The  mixture  should  be  agitated  three 
or  four  times  a  day.  After  two  days  it  becomes  colored  and  emits  vapors. 
When  completely  cold  the  acid  is  saturated  with  a  mixture  consisting  of  500 
grams  of  calcium  carbonate  in  2  kilograms  of  water.  The  resulting  product  is 
allowed  to  stand  for  two  or  three  hours,  when .  saturation  is  completed  by  a 
further  careful  addition  of  calcium  carbonate  and  water. 
The  solution  is  filtered,  precipitated  with  alcohol,  the  precipitate  collected 
by  decantation  and  allowed  to  become  air-dry  ;  it  is  then  dissolved  in  cold 
water,  filtered,  and  the  solution  brought  very  carefully  to  dryness. 
When  thus  obtained  the  salt  is  white,  somewhat  crystalline  powder,  soluble 
in  fifteen  parts  of  cold  water,  almost  insoluble  in  boiling  water,  and  insoluble 
in  alcohol.  The  solution  does  not  give  the  reaction  of  phosphoric  acid  when 
mixed  with  ammonium  molybdate.  The  use  of  this  salt  has  become  estab- 
lished in  some  of  the  hospitals  of  Paris.  Its  especial  value  lies  in  its  perfect 
neutrality  and  in  the  readiness  with  which  it  is  assimilated. 
