CHINESE  POISONS. 
61 
From  these  experiments  it  appears  that  the  presence  of  tart- 
rates, tartrate  of  antimony,  or  free  tartaric  acid  with  pure  strych- 
nine, does  not  affect  the  reaction  with  bichromate  of  potash  and 
sulphuric  acid  ;  but  that  it  becomes  less  sensitive  with  nitrate  of 
strychnine,  and  fails  altogether  with  an  excess  of  tartrate  of  anti- 
mony. The  probable  reason  of  this  is,  that  the  nitric  acid  set 
free  by  the  action  of  the  sulphuric  acid  decomposes  the  tartaric 
acid,  giving  rise  to  products  of  decomposition  which  exert  a  vio- 
lent reducing  action  upon  the  chromic  acid. 
On  the  other  hand,  the  characteristic  reaction  is  produced 
with  perfect  certainty  by  peroxide  of  lead  and  sulphuric  acid, 
even  in  the  presence  of  tartrates,  although  nitrate  of  strychnine 
be  employed. 
As  a  matter  of  course,  when  in  judicial  cases  nitrate  of  strych- 
nine and  tartaric  acid  coexist  in  the  substance  to  be  investigated, 
by  the  employment  of  the  process  of  Stass,  the  strychnine  is  ob- 
tained as  such,  and  not  in  the  form  of  a  salt,  so  that  the  above 
facts  would  have  no  influence  upon  the  result.  In  examining  a 
powder  consisting  of  nitrate  of  strychnine  and  tartrates,  the 
nitrate  must  be  converted  into  pure  strychnine,  or  the  reaction 
with  peroxide  of  lead  and  sulphuric  acid  must  be  employed;  this, 
indeed,  should  be  preferred  in  all  cases  when  there  are  no  data 
regarding  the  nature  of  the  substance  under  investigation  
London  Ohern.  Qaz.9  October  15,  1857,  from  Liebigs  Annalen. 
August  1857. 
CHINESE  POISONS. 
By  D.  J.  Macgowan,  M.  D.,  Ningpo. 
■ 
[The  writer  of  the  following  has  resided  in  China,  engaged  in 
medical  practice,  during  the  last  thirteen  years.  His  extensive 
acquaintance  with  the  Chinese  language,  and  with  the  literature 
of  Chinese  science,  is  such  as  to  justify  confidence  in  the  accu- 
racy of  his  statements. — Ed.  Edinburgh  Medical  Journal^ 
In  consequence  of  the  atrocious  attempt  of  the  Cantonese  to 
poison  the  foreign  community  at  Hong-Kong,  applications  have 
been  made  to  us  from  various  quarters  for  information  on  poisons 
known  to  the  Chinese.  An  investigation  of  Chinese  toxicology 
would  require  much  time  and  special  study,  which  we  despair  of 
