ON  PHYSALINE. 
135 
known,  from  that  upon  the  fixed  and  caustic  alkalies ;  in  the 
latter  case,  an  iodide  and  iodate  of  the  metal  is  formed,  which 
may  be  separated  either  by  alcohol,  which  leaves  the  iodate  un- 
touched, or  the  iodate  may  be  converted,  by  exposure  to  a  red 
heat,  into  iodide.  By  acting  on  ammonia  with  iodine,  only  a 
small  portion  of  iodide  of  ammonium  is  formed,  accompanied  by 
that  most  formidable  substance,  iodide  of  nitrogen,  a  substance 
whose  explosive  properties  render  it  an  operation  of  danger  to 
prepare  it  in  large  quantities  ;  but  if,  instead  of  using  caustic 
ammonia,  a  solution  of  sulphide  of  ammonium  be  used,  the  re- 
action which  ensues  is  perfectly  safe,  and  gives  us  the  salt  in 
question  very  readily.  The  operation  is  very  simple.  A  quan- 
tity of  pure  iodine  is  placed  in  a  flask  with  a  small  quantity  of 
water,  and  sulphide  of  ammonium  added  to  it  till  the  liquid  loses 
its  red  color,  and  is  turbid  only  from  separation  of  sulphur ;  the 
flask  is  then  agitated  till  the  sulphur,  for  the  most  part,  agglo- 
merates into  a  mass,  the  liquid  poured  off,  and,  if  necessary, 
ammonia  added  to  it  till  it  manifests  a  slightly  alkaline  reaction, 
and  then  boiled  till  all  odor  of  sulphuretted  hydrogen  and  of 
ammonia  is  lost,  then  filtered,  which  is  done  with  great  facility, 
and  evaporated  at  a  boiling  heat,  constantly  stirring  from  the 
edges  of  the  vessel,  till  it  becomes  a  pasty  mass,  when  it  is  im- 
mediately transferred  to  a  water  bath,  and  the  stirring  continued 
till  the  salt  is  dry.  It  then  forms  a  beautifully  white  and  crys- 
talline powder,  which  will  keep  for  some  time,  if  carefully  ex- 
cluded from  the  air,  but  which,  after  the  lapse  of  a  few  weeks, 
becomes  yellowish,  and  at  last  brown  ;  it  may,  however,  be  easily 
restored,  by  adding  a  little  solution  of  sulphuretted  hydrogen  till 
colorless,  filtering,  and  evaporating  to  dryness.  By  means  of 
this  process,  a  pound  of  the  substance  may  be  procured,  in  a 
perfectly  pure  condition,  in  a  couple  of  hours,  while  by  the  old 
method,  a  much  longer  time  would  be  necessary,  and  the  product 
be  not  so  good  Annals  of  Fharm.,  Jan,,  1853. 
ON  PHYSALINE. 
By  V.  Dessaignes  and  J.  Chautard. 
The  bitter  principle  of  Pliysalis  alkekengi  has  been  employed 
for  some  time  with  success  in  the  treatment  of  fever,  and  the 
