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SEPARATION  OF  TIN  AND  ARSENIC. 
an  extremely  large  amount  of  each,  producing  a  powerfully  tran- 
quilizing  effect,  without  even,  in  some  cases,  causing  sleep. 
The  strychnia  was  also  used  in  substance  to  the  extent  of  J 
and  J  grain  closes  while  I  was  surgeon  of  the  11th  U.  S.  C.  I., 
at  Memphis,  in  1864-65.  The  effect  was  good,  but  not  so  per- 
manent as  the  pill  formula. 
I  will  here  relate  a  singular  phenomenon.  Nearly  all  cases 
of  chronic  diarrhoea  amongst  the  Southern  blacks  terminated, 
after  a  lingering  illness,  fatally.  Nearly  all  cases  among  those 
from  Missouri,  Kentucky  and  Northern  Tennessee  terminated 
in  complete  cure.  *  *  *  *  *  I  have  never 
seen  a  case  of  cholera  since  I  was  a  student  in  1862—63,  but 
propose  to  use  some  such  treatment  as  already  mentioned  should 
it  visit  this  vicinity.  Discussion  in  reference  to  changes  in  the 
ganglionic  system  by  disease  and  medication,  I  forbear.  I  only 
state  a  few  facts. — Cincinnati  Lancet  and  Observer,  May,  1867. 
ON  THE  SEPARATION  OF  TIN  AND  ARSENIC. 
By  Professor  Wohler. 
This  method  is  based  upon  the  solubility  of  sulphide  of 
arsenic  in  bisulphite  of  potash,  which  does  not  dissolve  sulphide 
of  tin.  The  mass,  oxidized  by  nitric  acid,  is  allowed  to  digest 
with  sulphur  and  caustic  potash  till  solution  is  complete,  (or  till 
the  formation  of  a  metallic  oxysulphide,  which  is  separated  by 
filtration).  The  liquid,  treated  by  excess  of  sulphurous  acid,  is 
allowed  to  rest  for  some  time,  and  is  then  evaporated  till  two- 
thirds  of  the  water  and  all  the  sulphurous  acid  have  gone  off. 
Filter  off  the  sulphide  of  tin,  and  wash  it,  not  with  water,  which 
must  not  be  used  here,  but  with  a  concentrated  solution  of  chlo- 
ride of  sodium.  This  may  be  removed  from  the  precipitate  by 
means  of  a  slightly  acid  solution  of  acetate  of  ammonia,  but 
the  liquor  so  obtained  must  not  be  added  to  the  washing  waters 
charged  with  salt.  The  sulphide  of  tin,  when  dried,  may  be 
converted  into  oxide  of  tin  by  roasting  in  contact  with  air.  The 
arsenic  which  the  liquid  contains  in  the  state  of  arsenious  acid 
may  be  precipitated  by  a  current  of  sulphuretted  hydrogen. — 
Lond.  Chem.  News,  June  14,  1867. 
