174  laster's  method  of  preparing  sulph.  of  manganese. 
scription  "  at  the  next  visit."  The  patient,  preferring  the  origi- 
nal to  a  copy,  obtains  it — thus  depriving  the  apothecary  of  the 
means  of  recovering  the  debt,  should  compulsion  become  necessary, 
and  of  exculpating  himself,  should  any  untoward  circumstance 
occur. — Med.  Press  and  Circ,  Oct.  80;  1867. 
LASTER'S  NEW  METHOD  OF  PREPARING  THE  SULPHATE 
OF  MANGANESE. 
Communicated  by  Alexander  J.  Semmes,  M.  D. 
Visiting  Physician  to  the  Charity  Hospital,  New  Orleans,  La. 
The  various  combinations  of  manganese  have  been  employed 
comparatively  but  a  short  time  in  pharmaceutical  operations, 
and  in  the  treatment  of  disease  ;  the  economy  of  their  prepara- 
tion being  but  partially  understood,  it  was  with  the  hope  of 
rendering  their  preparation  easier  that  Mr.  Laster,  the  accom- 
plished Chemist  of  the  Charity  Hospital,  was  induced,  after 
careful  examination,  to  suggest  his  new  process  to  the  Pharma- 
ceutist. 
Among  the  more  important  salts  of  manganese  susceptible  of 
therapeutic  application,  may  be  mentioned  the  sulphate,  carbo- 
nate, phosphate,  iodide,  and  chloride  of  manganese  ;  the  sul- 
phate is,  of  this  number,  the  most  important  from  its  use  as  a 
technical  and  medicinal  agent ;  it  is  manufactured  upon  the 
large  scale  for  dyeing  purposes  by  heating  a  mixture  of  sulphate 
of  iron  and  binoxide  of  manganese  to  redness  ;  the  sulphate  is 
decomposed  at  the  high  temperature,  becoming  sesquioxidized  at 
the  expense  of  a  portion  of  the  acid,  the  undecomposed  acid 
uniting  with  a  portion  of  protoxide  of  manganese  '  produced 
under  the  circumstances. 
Some  would  suppose  this  to  be  an  easy  process,  and  that  the 
iron  was  sesquioxidized  at  the  expense  of  the  binoxide  instead 
of  the  acid  ;  but  such  is  not  the  case,  for  the  sulphate  of  iron 
commences  to  decompose  rapidly  at  a  low  red  heat,  whereas 
the  binoxide  requires  a  full  red  heat  for  its  partial  decomposi- 
tion. 
Again,  if  the  binoxide,  instead  of  the  acid,  sesquioxidizes  the 
iron,  there  should  be  no  elimination  of  sulphurous  acid,  which  is 
