24  New  Solvent  of  Phosphorus,  etc.  {k*J™XmT' 
and  the  result  of  my  experiments  upon  it  is  that  I  have  found  it  capable 
of  dissolving  four  or  more  per  cent,  of  phosphorus  ;  the  limit  of  its 
solubility  is  a  question  for  further  experiment. 
I  would  call  this  substance  phosphoretted  resin.  The  method  of 
preparing  it  is  thus  : — Take  a  strong  wide-mouthed  well-stoppered 
bottle  and  weigh  it,  then  melt  a  quantity  of  resin  sufficient  to  fill  the 
bottle  ;  let  the  bottle  be  warmed,  then  pour  in  the  resin  to  nearly  but 
not  quite  fill  the  bottle,  reweigh,  and  for  every  ninety-six  parts  of 
resin  take  four  of  phosphorus.  Now  observe  that  the  resin  is  in  a 
fluid  state  ;  if  so.  add  the  phosphorus,  and  fix  the  stopper  tightly. 
Place  in  a  sand-bath  previously  warmed,  and  apply  heat  to  200°  C, 
or  892°  F.  ;  digest  at  this  temperature,  and  shake  frequently  until 
the  phosphorus  is  dissolved. 
The  kind  of  resin  to  be  used  in  this  preparation  is  the  black  trans- 
lucent variety,  know  in  commerce  as  rosin,  not  that  pale  yellowish 
kind  usually  met  with  in  chemists'  shops,  unless  it  has  previously  been 
deprived  of  its  water,  of  which  it  contains  a  varying  amount,  some- 
times ten  per  cent. 
In  conducting  the  process,  it  is  necessary  to  observe  the  following 
precautions  : — In  adding  the  phosphorus,  if  possible  let  it  be  in  one 
piece,  and  take  care  that  the  resin  is  previously  in  a  fluid  condition,  as 
then  the  phosphorus  readily  sinks  below  the  surface,  and  is  covered 
by  the  resin  ;  otherwise,  if  the  phosphorus  were  in  small  pieces  and  the 
resin  semi-fluid,  the  phosphorus  would  rest  on  the  half-hot  resin,  and 
speedily  take  fire  ;  but  by  observing  the  above  precautions,  this  acci- 
dent may  be  prevented. 
A  bottle  full  of  the  preparation  should  be  made  at  a  time,  as  I  find 
there  is  great  risk  of  accident  (having  had  one  myself)  if  the  vessel  is 
only  partly  filled.  The  phosphorus  is  also  volatilized,  and  deposited 
in  the  upper  portion  of  the  bottle. 
Keep  a  thermometer  in  the  sand-bath  during  the  process,  and 
maintain  the  temperature  between  200°  and  210°  C.  At  higher 
temperatures  the  resin  boils,  and  the  heat  is  liable  to  change  the 
phosphorus  to  the  red  amorphous  state. 
When  the  prepared  resin  has  cooled  it  is  difficult  to  remove  it 
unless  the  bottle  be  broken  ;  the  method  I  have  adopted  is  to  draw  it 
from  the  bottle,  when  partly  cooled,  under  hot  water. 
It  is  a  pharmaceutical  process  which,  like  many  others,  requires 
care  and  attention  to  ensure  success,  but  whatever  difficulties  may 
arise,  to  a  practical  person  a  remedy  will  suggest  itself 
