598      Examination  of  Solution  of  Chloride  of  Iron.  {  ^'"birrisso^"™' 
syrups  which  it  is  not  practicable  to  obtain  by  this  process  ;  the  former 
would  be  decomposed  by  the  continued  exposure  to  the  air,  and  in  the 
latter  case  the  solution  of  gum  is  too  tenacious  to  percolate  through 
the  sugar. 
With  these  exceptions,  I  believe  all  the  officinal  syrups,  together 
with  many  others  that  are  not  officinal,  may  be  prepared  by  cold  per- 
colation. The  principal  advantages  of  making  syrups  by  this  process 
are  : 
It  is  a  saving  of  expense  where  the  operator  has  to  create  a  fire  spe- 
cially for  that  purpose. 
It  is  a  saving  of  time,  as  it  does  not  require  attention  ;  for  when  the 
liquid  has  passed  you  know  you  have  a  saturated  solution. 
It  is  also  a  far  more  elegant  and  pleasant  means  of  preparing  them. 
EXAMINATION  of  SOLUTION  of  CHLORIDE  of  IRON. 
By  Homer.  McCoy. 
Read  at  the  Pharmaceutical  Meetings  No~uember  16th. 
It  has  been  suggested  that  the  solution  of  chloride  of  iron  is  olten 
very  deficient  in  strength.  A  sample  of  this  solution  was  obtained  and 
the  iron  estimated  volumetrically  by  a  standard  solution  of  perman- 
ganate of  potassium,  the  process  and  results  of  which  are  here  given  : 
The  first  step  was  to  reduce  the  ferric  chloride  to  ferrous  form,  which 
was  accomplished  by  means  of  nascent  hydrogen,  evolved  by  the  action 
of  dilute  sulphuric  acid  on  metallic  zinc  in  a  closed  apparatus,  which 
excludes  the  air  and  prevents  oxidation. 
Commercial  zinc  contains  a  small  proportion  of  iron,  and  the  amount 
present  in  the  zinc  used  was  '024  per  cent.,  which  must  be  considered 
in  accurate  work.  3*061  grams  of  zinc  were  used  in  this  estimation^ 
and  '024  per  cent.,  or  0"000735  gram  was  iron,  which  must  be 
deducted  from  the  final  result. 
l'926  gram  of  the  solution  of  ferric  chloride  was  placed  in  the 
flask  for  generating  the  hydrogen —  the  apparatus  closf  d  and  heat  applied. 
When  the  zinc  was  all  dissolved,  the  contents  were  cooled  quickly,  and 
then  washed  out  into  a  beaker,  about  300  cc.  of  distilled  water  added,, 
care  being  taken  that  there  be  an  excess  of  acid  in  the  solution,  and 
then  quickly  titrated  with  the  standard  solution  of  potassium  perman- 
gate  until  the  last  drop  perceptibly  colored  the  solution,  showing  oxida- 
