SUBLIMING  TEMPERATURES  OF  POISONS. 
241 
ON  THE  MELTING  AND  SUBLIMING  TEMPERATURES  OF 
THE  PRINCIPAL  POISONS,  ORGANIC  AND  INORGANIC. 
By  William  A.  Guy,  M.B,  F.R.S. 
Professor  of  Forensic  Medicine,  King's  College,  London,  etc. 
This  communication  does  not  exhaust  the  subject  of  which  it 
treats.  Its  aim  is  to  indicate  and  describe  a  simple  method  of 
procedure  by  which  a  new  element  is  added  to  the  natural  his- 
tory and  diagnosis  of  poisons.  It  is  a  very  obvious  development 
of  the  method  of  sublimation  described  in  previous  communica- 
tions to  the  4  Pharmaceutical  Journal;'*  and  it  will  be  seen  to 
have  the  special  recommendation  of  applying  heat  in  so  gradual 
a  manner  as  to  guard  against  the  chief  objection  to  Helwig's 
plan  still  more  completely  than  the  modification  I  have  already 
recommended.  It  may  be  well  to  add,  by  way  of  preventing 
any  possible  misconception  of  the  object  of  this  paper,  that  the 
experiments"  to  which  reference  will  be  made  are  limited  to  com- 
mercial specimens  of  poisons,  and  to  such  of  them  as  are  sold 
as  white  powders  or  colorless  crystals.  For  the  alkaloids  and 
active  proximate  principles  I  am  indebted  to  the  Messrs.  Morson, 
— as  I  am,  indeed,  for  almost  all  the  preparations  which  I  em- 
ploy. The  results  of  the  sublimation  of  the  alkaloids,  as  ob- 
tained from  solutions  of  their  salts,  and  from  organic  matters, 
must  be  the  subject  of  future  communications. 
If  any  excuse  were  needed  for  the  present  attempt  to  confer 
a  more  definite  character  on  the  test  of  heat  as  applied  to  poisons, 
it  would  be  found  in  the  fact  that  already,  in  all  works  on  toxi- 
cology, the  results  of  the  rough  method  of  procedure  with  the 
spirit-lamp  and  platinum-foil,  or  with  the  spirit-lamp  and  reduc- 
tion-tube, are  set  forth  with  many  of  the  poisonous  substances 
to  which  they  are  deemed  applicable.  The  following  may  be 
taken  as  a  fair  specimen  of  the  description  of  these  results  as 
obtained  with  the  spirit-lamp  and  platinum-foil  :• — 
1.  Arsenious  Acid. — Wholly  dissipated,  as  a  white  vapor,  at 
a  temperature  of  370°. 
2.  Corrosive  Sublimate. — Melts,   and   is  wholly  dissipated, 
*  See  papers  on  the  "  Sublimation  of  Alkaloids,"  '  Pharmaceutical 
Journal '  for  June,  July,  August,  September  and  October,  1867. 
16 
