A.m.  Jour.  Pharm. 
May,  1887. 
Ptomaines. 
253 
ize,  or  even  to  add  any  slight  excess  of  alkali  on  adding  the  sodi 
acetate  and  ferric  chloride.  It  also  serves  very  well  for  the  investiga- 
tion of  peptones  in  urine,  commencing  by  boiling  to  precipitate  albumin 
coagulable  by  heat,  and  terminating  as  above. 
II.  The  double  iodide  of  potassium  and  mercury  precipitates  albu- 
min and  the  peptones,  and  Tanret  has  shown  that  the  albuminous  pre- 
cipitate is  insoluble  in  boiling  acetic  acid,  whilst  the  peptone  pre- 
cipitate dissolves  completely.  Employing  these  reactions,  Georges  has 
established  a  much  more  rapid  method  as  follows : — Precipitate  by 
heat  all  the  coagulable  albumin ;  treat  the  urine  with  acetic  acid  and 
the  double  iodide,  wash  the  precipitate  on  a  filter  with  cold  water 
charged  with  acetic  acid  to  the  same  extent  as  the  urine  ;  wash  again 
with  the  same  acidified  water  boiling,  keeping  the  washings  apart. 
The  clear  liquid  obtained  gives  a  precipitate  on  cooling  if  the  least 
trace  of  peptonic  precipitate  has  been  dissolved.  It  is  only  necessary 
to  neutralize  in  order  to  obtain  a  solution  to  which  the  double  iodide 
test  can  be  applied. — Jour.  Chem.  Soc,  Feb.  1887,  188  ;  Jour.  Phar. 
Chim.  1886.  .   
PTOMAINES. 1 
By  H.  Beckurts. 
The  detection  of  poisonous  alkaloids  in  forensic  and  similar  cases  is 
greatly  increased  in  difficulty  owing  to  the  formation  of  ptomaines 
from  albuminoid  substances  of  animal  or  vegetable  origin,  more 
especially  as  the  ptomaines  in  their  general  chemical  reactions  bear 
great  resemblance  to  the  vegetable  alkaloids.  It  has  repeatedly 
occurred  in  criminal  cases,  that  the  two  classes  of  compounds  have 
been  confounded,  even  by  experts.  All  the  basic  nitrogenous  pro- 
ducts which  result  from  the  action  of  bacteria,  whether  of  disease  or 
decomposition,  must  be  considered  as  ptomaines ;  and  perhaps  also 
certain  definite  poisonous  basic  substances,  the  leucomaines,  which 
according  to  Gautier  are  formed  during  life  in  man  and  the  higher 
animals. 
Until  very  recently,  only  ptomaines  of  unknown  composition  had 
been  isolated,  and  in  all  cases  by  the  methods  of  Stas-Otto  and  Dra- 
gendorff.  It  is  mainly  to  Brieger's  investigations  during  the  past 
four  years,  that  we  are  indebted  for  a  mo le  accurate  knowledge  of 
1Arth.  Pharm.,  1886,  1041-1065.  Reprinted  from  Jour.  Chem.  Soc,  April, 
1887. 
