Am.  Jour.  Pharm.  ) 
Nov.  1875.  J 
Editorial, 
haste  to  inform  our  readers  at  once,  by  inserting  a  printed  slip,  of  the  danger 
connected  with  the  materials  employed.  The  danger  appears  to  be  in  the  combina- 
tion of  bromine  and  phosphorus,  and  Professor  Markoe  has  failed  to  point  out  this, 
danger,  although  he  recommended  his  process  because  it  was  more  expeditious  and 
safer  than  that  of  the  Pharmacopoeia.  We  have  prepared,  and  seen  prepared  by 
others,  large  quantities  of  phosphoric  acid  by  oxydizing  phosphorus  with  nitric  acid> 
and  have  never  noticed  any  explosion,  the  dilution  of  the  phosphoric  acid  having 
been  properly  attended  to.  But  for  the  new  process  it  was  claimed  that  without 
danger  of  explosion  it  could  be  prepared  even  with  concentrated  nitric  acid.  The 
directions  given  in  the  paper  read  at  Boston,  are  as  follows  : 
Take  of      Phosphorus  one  part  ; 
Nitric  acid,  spec.  grav.  i'42,  six  parts  ; 
Water  one  part ; 
Bromine  or  hydrobromic  acid,  a  sufficient  quantity. 
Put  the  phosphorus  and  nitric  acid  into  a  glass  flask,  holding  at  least  double  the  amount  of  all  the 
materials,  place  in  the  neck  of  the  flask  a  glass  funnel  and  invert  a  smaller  funnel  over  the  first  one  ;  pour 
into  the  flask  a  few  drops  of  bromine  or  hydrobromic  acid,  and  when  the  reaction  has  fairly  started  place 
the  flask  in  a  pan  of  water,  &c. 
This  is  the  material  part  of  the  process,  the  remainiug  operations  consisting  of 
decanting  the  liquid  from  the  undissolved  phosphorus,  and  evaporating  it  in  order  to 
expel  the  bromine,  iodine  and  excess  of  nitric  ajid.  It  will  be  observed  that  while 
on  the  one  hand  a  feiv  drops  of  bromine  is  a  very  uncertain  quantity,  on  the  other 
hand  it  is  not  stated  that  the  bromine  should  be  added  drop  by  drop,  waiting  after 
each  addition  until  the  reaction  has  taken  place,  and  that  the  vessel  is  directed  to 
be  placed  in  water  only  after  the  reaction  has  commenced. 
Dr.  Pile  mixed  in  a  glass  retort  6  ounces  of  water  and  36  ounces  of  nitric  acid,  of 
1-42  sp.  gr.,  and  after  placing  the  retort  in  the  yard  in  a  rope  ring  resting  upon  an 
empty  barrel,  added  6  ounces  of  phosphorus,  and  then  poured  slowly,  through  the 
neck  of  the  retort,  a  fluid  drachm  of  bromine,  having.a  vessel  with  cold  water  handy 
to  place  the  retort  in  as  soon  as  the  reaction  should  become  brisk.  The  result  was, 
before  any  brisk  reaction  could  be  observed,  a  most  violent  explosion,  whereby  the 
retort  was  shattered  into  atoms,  the  burning  phosphorus  carried  in  minute  pieces  in 
all  directions,  the  rope  ring  thrown  upon  the  roof  of  the  house,  the  barrel  blown  to 
pieces  and  portions  of  it  driven  into  the  ground.  Dr.  Pile  was  injured  upon  the  left 
side  of  his  face  by  minute  fragments  of  glass  and  minute  particles  of  phosphorus, 
but  more  severely  by  the  hot  nitric  acid.  Fortunately,  from  his  position  in  watching 
the  reaction,  he  escaped  meeting  with  any  serious  injury,  is  again  about  and  has 
again  tried  the  reaction  with  satisfactory  results,  adding  the  bromine  in  drops,  and 
waiting  after  each  addition  until  the  reaction  subsides.  The  force  of  the  explosion 
seemed  to  be  directed  mainly  downwards  and  upwards,  not  a  window  being  broken  in 
the  adjoining  buildings  5  but  the  force  was  sufficiently  strong  to  sweep  chemicals  from 
the  glass  plates  upon  which  they  had  been  left  in  the  drying  room,  located  in  the 
third  story,  where  the  windows  had  been  left  open. 
W hat  has  caused  this  violent  explosion.?  Perhaps  the  formation  of  bromide  ot 
nitrogen  first  suggests  itself  as  the  cause,  since  it  is  stated  to  be  as  violently  explosive 
as  the  corresponding  chlorine  compound.  Balard,  the  discoverer  of  bromine  (1826), 
noticed  already  that  bromine  and  phosphorus  unite  with  incandescence,  and  H.  Rose 
