228         Pharmaceutical  Colleges  and  Associations.  {Amji^876am' 
Markoe,  suggests  a  new  process  for  preparing  diluted  phosphoric  acid  by  the  action 
of  bromine  upon  phosphorus  in  the  presence  of  nitric  acid.  This  is  an  important 
modification  of  Pettenkofefs  process,  proposed  in  1866,  wherein  the  oxidation  of 
the  phosphorus  is  effected  by  the  agency  of  iodine  and  subsequently  water,  some 
nitric  acid  being  finally  used  to  effect  the  complete  oxidation  of  any  phosphorous 
acid  present.  While  the  committee  acknowledge  the  entire  safety  of  the  new  pro- 
cess, if  properly  managed,  yet  they  cannot  refrain  from  taking  into  consideration 
the  slowness  of  the  process  if  conducted  without  very  frequent  supervision,  but 
more  especially  the  introduction  of  a  new  element  of  danger,  requiring  certain  pre- 
cautions j  and  they  cannot  admit  that  any  danger  is  connected  with  the  more  expe- 
ditious "  Pharmacopoeia  "  process,  even  when  carried  out  on  a  large  scale,  if  the 
directions  of  the  "  Pharmacopoeia,"  particularly  in  regard  to  the  strength  of  the 
nitric  acid,  are  adhered  to. 
Mr.  Louis  Dohme's  and  Prof.  Remington's  papers  treat  substantially  of  the  same 
subjects,  though  the  former  enters  more  deeply  into  the  conditions  connected  with 
the  conversion  of  one  into  another  variety  of  phosphoric  acid.  Both  papers  point 
out  a  notable  difference  in  the  strength  of  the  dilute  phosphoric  acid  as  prepared  by 
the  two  processes  of  the  "  Pharmacopoeia,"  and  notice  again  the  presence  of  impu- 
rities (soda)  in  the  commercial  glacial  acid,  which  retard  but  do  not  prevent  its 
complete  change  into  orthophosphoric  acid. 
Graham,  in  his  classical  investigations  of  the  phosphoric  acids,  has  shown  that 
the  glacial  acid  may  become  contaminated  with  impurities  from  the  vessels  in  which 
it  may  be  prepared,  and  such  impurities  were  proven  to  exist  in  commercial  acid 
as  early  as  i860,  ("Amer.  Jour.  Phar.,"  i860,  p.  193).  The  introduction  of  soda 
for  the  purpose  of  hardening  glacial  phosphoric  acid  was  first  noticed  by  Brescius 
in  1867,  and  subsequently  confirmed  by  Prof.  Prescott  and  by  the  authors  of  the 
two  papers  mentioned.  Regarding  the  conversion  of  meta-  and  pyrophosphoric  into 
orthophosphoric  acid,  Graham  has  observed  that  it  may  be  done  by  boiling  their 
aqueous  solutions,  more  rapidly  in  the  presence  of  free  mineral  acids.  The  conver- 
sion with  water  alone  is  best  effected,  according  to  Littleton  Thompson  (1874), 
by  heating  the  concentrated  solution,  for  which  purpose  Mr.  Dohme  finds  a  temper- 
atureof  from  280°  to  3000  F.  to  be  required. 
The  aqueous  solutions  of  metaphosphates  were  found  by  Graham  to  be  converted 
gradually  into  orthophosphates,  but  to  effect  a  similar  change  of  the  pyrophosphates 
the  presence  of  a  mineral  acid  was  found  necessary,  and,  according  to  Weber,  the 
most  rapid  change  is  produced  by  sulphuric  acid.  Reynoso,  however,  succeeded  in 
1852,  in  changing  the  meta- and  pyrophosphates  readily  into  orthophosphates  by 
exposing  their  solutions  to  a  temperature  of  2800  C.  (5360  F.)  As  far  as  the 
behavior  to  ferric  chloride  is  concerned,  the  conversion  may  be  completed  by  pro- 
longed boiling  in  the  presence  of  nitric  acid. 
The  function  of  the  pancreatic  liquid,  according  to  Lehmann,  was  first  recog- 
nized by  Valentin  to  consist  in  transforming  into  sugar  such  starch  which  may  arrive 
in  the  duodenum  in  an  unaltered  condition.  The  discovery,  by  Claude  Bernard, 
that  the  pancreatic  liquid  is  capable  of  decomposing  neutral  fats  into  fatty  acids 
and  glycerin,  has  been  admitted  by  all  subsequent  investigators ;  but  the  availability 
of  this  property  for  the  purpose  of  digestion,  as  asserted  by  Bernard,  has  been 
