ARSENIC  IN  AMERICAN  SULPHURIC  ACID.  235 
diluted  solution  deposits  a  reddish-brown,  humus-like  substance, 
devoid  of  narcotic  properties. 
Besides  atropia,  there  is  present  in  belladonna  a  volatile  base, 
which  has  been  mentioned  by  Brandes,  and  has  been  separated 
by  Luebekind  as  a  crystalline  sublimate  on  distilling  the  leaves 
with  caustic  potassa.  The  extract  of  belladonna  likewise  yields 
a  volatile  base  at  ordinary  temperatures  in  contact  with  caustic 
alkaloids.  It  remains  then  to  be  seen  in  what  relation  these  four 
alkaloids  stand  to  each  other  and  to  atropia.  F.  F.  M. 
ON  THE  CONTAMINATION  OF  AMERICAN  SULPHURIC  ACID 
WITH  ARSENIC. 
By  John  M.  Maisch. 
The  query*  allotted  to  me  for  investigation,  is :  "  Do  any  of 
the  best  samples  of  sulphuric  and  other  mineral  acids  of  Ame- 
rican origin,  contain  appreciable  amounts  of  arsenic?" 
The  mode  of  investigating  the  subject  was  as  follows : 
The  sulphuric  acid  was  treated  directly  in  Marsh's  apparatus, 
with  pure  zinc,  and  the  hydrogen  evolved  treated  in  the  well 
known  manner.  The  nitric  acid  was  partly  saturated  with  pure 
carbonate  of  soda,  evaporated  to  dryness,  the  residue  treated 
with  an  excess  of  pure  sulphuric  acid,  heated  to  drive  off  the 
nitric  acid,  re-dissolved  in  water,  and  now  examined  in  Marsh's 
apparatus.  The  muriatic  acid  was  diluted  with  water,  sulphuret- 
ted hydrogen  was  passed  through  it,  and  the  dried  precipitate, 
after  being  mixed  with  dry  carbonate  of  soda  and  cyanide  of 
potassium,  was  heated  in  a  current  of  dry  carbonic  acid  ga?, 
according  to  the  method  of  Fresenius  and  Baba. 
I  have  examined  the  three  mineral  acids  named,  manufactured 
by  Kalbfleisch,  of  New  York,  Powers  &  Weightman,  Rosengar- 
ten  &  Sons  and  Charles  Lennig,  of  Philadelphia,  and  have  in 
no  case  met  with  any  trace  of  arsenic. 
This  result  appears  to  speak  well  for  American  acids.  But 
it  must  be  remembered  that  the  query  is  therewith  not  fully  an- 
swered. The  origin  of  arsenic  in  the  mineral  acids  is  to  be 
looked  for  in  the  sulphur,  which  frequently  contains  traces  or 
larger  proportions  of  arsenic  in  the  form  of  sulphides.  The 
arsenic  is  volatilized  when  the  sulphur  is  burned  in  the  manufac- 
ture of  sulphuric  acid,  and  if  this  acid  is  contaminated  with  this 
