ON  THE  COLOR-TESTS  OE  STRYCHNIA,  ETC. 
235 
evidences  of  the  presence  of  the  poison  were  afforded  by  a  tran- 
sient yet  distinct  play  of  colors. 
The  other  portion  (6)  was  treated  directly  with  a  measure  of 
chloroform  and  two  measures  of  the  caustic  solution.  After 
mixing  these  carefully  together,  the  chloroform  was  drawn  off, 
placed  in  a  capsule,  and  evaporated  spontaneously.  A  very 
delicate  filmy  deposit,  of  a  white  color  and  bitter  taste,  was  ob- 
served in  the  capsule.  A  part  of  this  gave,  with  sulphuric  acid 
and  ferricyanuret  of  potassium,  a  distinct  but  evanescent  change 
of  colors,  indicating  positively  the  presence  of  strychnia. 
To  determine  more  satisfactorily  the  precise  nature  of  the  de- 
posit obtained  from  this  experiment,  I  evaporated,  upon  a  slip 
cf  glass,  drop  after  drop  of  the  chloroformic  solution,  until  an 
appreciable  deposit  was  procured,  and  to  this  a  drop  of  dilute 
nitric  acid  was  added.  When  dry,  it  was  placed  under  a  micro- 
scope at  a  magnifying  power  of  100  diameters,  and  a  crop  of 
well-defined  crystals  of  the  nitrates  of  strychnia  and  brucia  was 
apparent. 
This  experiment  proves  conclusively  that  strychnia  in  minute 
quantities  can  be  regained  from  organic  mixtures,  notwithstand- 
ing the  presence  of  three  times  its  weight  of  sulphate  of  mor- 
phia. 
In  conclusion,  I  may  be  permitted  to  offer  to  those  who  shall 
be  called  upon  to  determine  the  presence  or  absence  of  strychnia 
in  cases  of  suspected  poisoning,  a  few  practical  suggestions, 
viz : — 
1.  In  testing  for  minute  portions  of  the  poison,  success  or 
failure  depends  entirely  upon  the  care  given  to  the  details  of  the 
process. 
2.  In  examining  the  contents  of  a  stomach,  the  employment 
of  heat  is  not  required  for  the  detection  of  strychnia,  nor  should 
any  unnecessary  fluid  be  added  which  might  require  subsequent 
evaporation.  Equal  measures  of  acetic  acid  and  cold  water,  in 
sufficient  amount  to  thoroughly  acidulate  the  mass,  are  all  that 
is  requisite  to  extract  any  alkaloids  or  their  salts  that  may  be 
present,  and,  to  insure  success,  these  must  be  reduced  to  the 
solid  state. 
4.  In  the  application  of  reagents  for  the  production  of  the 
color-tests,  care  should  be  observed  not  to  add  any  more  sul- 
