PHOSPHORUS  GLUE  AND  CHLORIDE  OP  AMMONIUM.  49 
PRODUCTION  OF  PHOSPHORUS,  GLUE,  AND  CHLORIDE 
OF  AMMONIUM. 
Hr.  Gentele  suggests  that  the  production  of  phosphorus,  which 
has  within  the  last  few  years  become  so  much  more  important  a 
branch  of  chemical  industry,  may  be  advantageously  combined 
with  the  production  of  glue,  sal  ammoniac,  and  ferrocyanides. 
The  raw  materials  for  the  preparation  of  ferrocyanide  are  to 
be  charred  in  the  ordinary  manner,  and  the  liquid  as  well  as 
solid  carbonate  of  ammonia,  obtained  at  the  same  time,  is  to  be 
used  for  making  sal  ammoniac. 
The  separation  of  the  fat  from  the  bones  is  effected  best  by 
boiling  them  with  water.  The  fat  thus  obtained  serves  for 
making  soap.  The  bones  are  from  time  to  time  taken  out  of  the 
water  by  means  of  rakes,  and  fresh  bones  put  in  until  the  liquid 
becomes  gelatinous.  This  may,  according  to  circumstances,  be 
used  as  manure,  or  as  food  for  pigs. 
The  phosphate  of  lime  is  then  separated  by  digesting  the  bones 
in  hydrochloric  acid  (1*03  to  1*05  sp.  gr.)  until  they  become  soft 
and  transparent.  Fresh  bones  yield  the  largest  amount  of  fat 
and  also  of  gelatine;  in  old  bones  the  gelatine  is  for  the  most 
part  decomposed.  Even  in  fresh  bones  the  amount  of  gelatine 
varies  very  much,  some  containing  45  per  cent.,  and  others  only 
30,  or  even  less. 
The  bones  from  which  phosphate  of  lime  has  been  extracted 
by  hydrochloric  acid  must  be  well  washed  with  water,  and  lastly 
with  lime  water.  The  gelatinous  residue  is  dried  in  the  air,  and 
then  exposed  to  the  action  of  steam  in  a  well  closed  vat,  furnished 
with  one  or  more  perforated  false  bottoms.  After  a  short  time, 
a  stream  of  liquid  gelatine  flows  out  of  the  vat,  sufficiently  con- 
centrated to  be  run  into  moulds  and  cut  into  sheets.  When  a 
more  dilute  solution  begins  to  flow  off,  the  remaining  lumps  of 
gelatine  are  taken  from  the  vat  and  boiled  with  the  thin  solution, 
or  with  water,  until  completely  dissolved,  the  liquid  evaporated, 
and  run  into  moulds. 
For  obtaining  phosphate  of  lime  and  sal  ammoniac  two  me- 
thods may  be  adopted :  The  solution  of  phosphate  of  lime  in 
hydrochloric  acid  may  be  precipitated  by  the  crude  solution  of 
carbonate  of  ammonia,  obtained  from  the  charring  of  the  raw 
4 
