196  PREPAKATION  OF  MISTUEA  FERRI  COMPOSPTA. 
Thus  having  detected  the  presence  of  this  cupreous  salt,  in 
large  quantity,  I  did  not  consider  it  necessary  to  prosecute  the 
enquiry  any  further. 
Guy  ("  Principles  of  Forensic  Medicine,")  says  truly,  that 
"  poisoning  with  the  salts  of  copper  is  of  very  rare  occurrence  ;" 
and  adds  :  "  they  are  ill  adapted  to  the  purposes  of  the  murderer  ; 
and,  for  the  same  reason,  are  not  likely  to  be  taken  acci- 
dentally." The  reason  alluded  to,  is,  of  course,  the  taste  and  co- 
lor of  these  salts  ;  properties  so  peculiar,  that  suspicion  would  be 
readily  excited  by  them. 
It  is  in  reference  to  this  point  that  the  case  acquires  additional 
importance  ;  for  neither  the  taste  nor  color  betrayed  the  poison- 
.ous  nature  of  the  article  swallowed;  indeed  they  rather  served 
to  give  assurance  that  no  mistake  had  been  committed.  Carbo- 
nate of  copper  has  so  near  no  taste,  that  were  it  not  for  its  co- 
lor, the  presence  of  a  cupreous  salt  would  hardly  be  suspected ; 
and  yet  in  the  case  before  us,  the  color  itself  only  added  to  the 
feeling  of  security.  So  that  this  instance,  in  which  copper  was 
"taken  accidentally,"  furnishes  a  remarkable  exception  to  the 
general  rule. 
The  rare  occurrence  of  poisoning  by  salts  of  copper,  makes  it 
desirable  that  every  example  of  the  kind  should  find  its  place  on 
record,  until  our  information  on  the  toxicology  of  the  salts  of 
this  metal,  is  brought  nearer  to  completion.  As  it  is,  I  find  but 
a  solitary  case  of  poisoning  by  carbonate  of  copper  in  any  pub- 
lication which  I  have  examined  ;  and  that  case  is  cited  by  Tay- 
lor ("  On  Poisons,")  as  occurring  in  France.  So  deficient  is  our 
knowledge  on  this  subject  that  no  Dispensatory,  no  treatise  on 
i poisons,  no  medico-legal  or  other  writings  consulted,  say  one 
word  respecting  the  quantity  of  carbonate  of  copper  necessary 
to  display  deleterious  effects.  In  the  case  now  reported,  it  is, 
therefore,  of  importance  to  recollect,  that,  on  the  supposition 
that  the  carbonate  was  equally  diffused  through  the  mixture, 
three  tenths  of  a  grain  produced  twice  in  the  same  person  vio- 
lent and  prostrating  results ;  and  that  the  admixture  of  myrrh, 
sugar,  and  sulphate  of  potash,  with  the  cupreous  carbonate,  did 
not  prevent  those  results.  That  all  the  sulphate  of  copper  was 
decomposed,  is  apparent  from  the  inaction  of  the  needle  in  the 
turbid  filtrate  before  it  was  acidulated. 
