PREPARATIONS  OF  ARSENIC. 
345 
ing  more  or  less  malleable  alloys,  whilst  aluminium  cannot  bear 
more  than  10  per  cent,  of  foreign  metal,  or  enter  into  combina- 
tion itself  in  greater  proportion,  without  greatly  modifying  the 
durability  of  the  metal  with  which  it  is  alloyed. — Ohem.  Qaz.j 
March,  1857,  from  Comptes  Rendus,  Feb.  16,  1857. 
THE  PREPARATIONS  OF  ARSENIC  EMPLOYED  IN  MEDICINE. 
By  A.  F.  Haselden. 
In  introducing  this  subject,  he  said  he  had  nothing  new  to  of- 
fer with  reference  to  the  medicines  he  was  about  to  notice,  but  he 
thought  some  benefit  might  result  from  a  discussion  of  the  rela- 
tive merits  of  the  different  compounds  of  preparations  of  arsenic 
used  in  medicine,  with  the  view  of  eliciting  the  opinions  of  those 
present  as  to  which  of  them  ought  to  be  ordered  in  our  Pharma- 
copoeia. At  present  there  were  only  two  preparations  of  arsenic 
in  the  London  Pharmacopoeia,  while  there  were  several  others 
frequently  used  in  medicine,  and  ordered  in  other  Pharmacopoeias. 
He  proposed  briefly  to  describe  or  refer  to  the  principal  arseni- 
cal compounds  in  use,  so  as  to  bring  the  subject  fairly  before  the 
meeting,  and  present  the  points  upon  which  the  expression  of 
opinion  was  desired. 
Liquor  Potasses  Arsenitis,  of  the  London  Pharmacopoeia, 
claimed  the  first  notice,  from  the  fact  of  its  having  maintained 
its  position  through  several  generations  of  Pharmacopoeias,  and 
of  its  being  more  generally  used  by  English  medical  practition- 
ers than  any  other  arsenical  preparation.  By  many  medical  men 
this  was  the  only  preparation  of  arsenic  ever  prescribed,  but 
whether  this  circumstance  arose  from  their  considering  it  supe- 
rior to  all  the  others,  or  from  their  being  unwilling  to  try  the 
effects  of  any  new  preparations  of  so  powerful  an  agent  as  ar- 
senic, he  was  unable  to  say.  There  appeared  to  be  a  difference 
of  opinion  as  to  whether  this  preparation  was  rightly  called  an 
arsenite  of  potash  or  not,  some  persons  contending  that  the  old 
name  of  Liquor  Arsenicalis  was  a  more  correct  one. 
Liquor  Arsenici  Chloridi  had  been  introduced  into  the  London 
Pharmacopoeia  of  1851  for  the  first  time.  It  was  understood  to 
be  intended  to  represent  an  old  preparation,  known  as  De  Val- 
