AmNJo°v.r;x876rin'}  The  diferent  Syrup  of  the  Phosphates.  495 
Take  of    Iron  wire  (No.  20),  .  .  240  grains 
Phosphoric  acid  (sp.  gr.  1*75),  .  3  oz.  by  weight 
Water,  .  .  .  .4  fluiduonces 
Dissolve  with  the  precautions  directed  above  in  the  formula  for 
Parrish's  syrup. 
Quinia  sulph.,  ....    625  grains 
Liq.  ammon., 
Distilled  water, 
Dilute  sulphuric  acid,  .  .  .  oa  q.  s. 
Precipitate  the  quinia,  secundum  artem,  and  wash  on  a  filter  with 
a  pint  of  very  cold  distilled  water,  press  strongly,  and  dissolve  in  half 
an  ounce,  by  weight,  of  phosphoric  acid,  diluted  with  an  ounce  of 
water  in  which  16  grains  of  strychnia  have  been  dissolved.  Mix  with 
the  solution  of  iron,  add  enough  distilled  water  to  make  the  whole 
measure  10  fluidounces,  and  mix  thoroughly  with  54  fluidounces  of 
simple  syrup.  The  resulting  syrup  will  contain  in  each  fluidrachm  1 
grain  ferrous  phosphate  Fe3P208,  1  grain  quinic  phosphate  (C20H24N2 
02)32H3P04,  and  ^  grain  of  strychnia. 
These  two  syrups  afford  good  examples  of  two  classes  of  syrups  that 
present  considerable  difficulties  in  manipulation  with  the  formulae  in 
general  use,  which,  I  think,  are  quite  removed  in  the  two  just  submitted, 
both  have  now  been  tested  on  a  large  scale  for  some  time,  and  found 
very  satisfactory  in  their  products.  No  originality  is  claimed  in  the 
use  of  metallic  iron  in  place  of  precipitated  ferrous  phosphate  ;  it  was, 
I  believe,  first  suggested  by  Mr.  W.  H.  Jones,  in  the  columns  of  the 
"  Pharmaceutical  Journal."  The  chief  point  that  I  would  press,  is  the 
importance  of  using  tribasic  (ortho)  phosphoric  acid,  H3P04 ;  both 
metaphosphoric  acid,  HPOs,  and  pyrophosphoric  acid,  H4P207,  if 
present  in  the  acid  to  even  a  small  extent,  are  certain  to  cause  trouble. 
The  precaution  given  as  to  filtering  the  solution  of  ferrous  phosphate 
will  be  found  useful  in  many  other  cases  ;  a  beakerful  of  solution  of 
ferrous  iodide  filtered  in  a  similar  manner,  with  a  layer  of  syrup  the 
eighth  of  an  inch  thick  floating  on  the  surface,  can  be  left  exposed  for 
24  hours  without  injury  to  the  solution.  It  is,  of  course,  necessary 
that  the  solution  should  have  the  greatest  specific  gravity. — Pharm. 
'Journ.  and  Trans.,  July  15,  1876. 
