^i)™r,\m"m'}      Contributions  to  Forensic  Chemistry.  59.5' 
resorbed  and  transformed  into  products  which,  like  urochloralic  acid,- 
do  not  show  the  reactions  of  chloral  hydrate. 
Detection  of  Phenol. — Experiments  were  made  by  Dr.  Woldemar 
Jacobson  for  the  purpose  of  isolating  and  recognizing  phenol.  The 
organic  mixtures,  100  ccm.,  were  macerated  for  a  day  with  400  ccm. 
of  alcohol,  the  filtrate  was  freed  from  alcohol  by  distillation  at  a  low 
temperature  and  under  reduced  pressure,  the  aqueous  residue  filtered, 
agitated  with  little  petroleum  benzin  for  the  separation  of  fat,  and 
then  repeatedly  shaken  with  benzol,  which  solvent  was  evaporated 
in  watch-glasses.    The  following  reactions  were  employed: 
Dragendorff  ?s  method:  The  residue  was  left  in  contact  at  ordinary 
temperatures  with  solution  of  mercuric  nitrate,  containing  a  little 
nitrous  acid ;  the  red  color  appears  in  half  an  hour  with  1  phenol 
in  100,000  mixture. 
Jacquemin's  method :  Dissolve  3  drops  of  colorless  aniline  in  50 
ccm.  of  water.  Dilute  5  or  10  drops  of  this  solution  with  5  ccm. 
of  water,  and  add  sufficient  solution  of  sodium  hypochlorite  (1 
sodium  carbonate;  1  chlorinated  lime;  10  water;  filter),  until  a 
distinct  violet  or  brown  color  is  produced.  Add  of  this  freshly  pre- 
pared mixture  to  the  phenol,  previously  mixed  with  ammonia  until 
the  liquid  is  colored  violet  or  brownish,  when  in  a  short  time  in  the 
presence  of  phenol  (1 : 50,000)  the  color  will  change  to  blue,  or  with 
less  phenol  (1 : 100,000)  to  green. 
Landolt's  reaction:  Cloetta  and  Schser  have  shown  that  the  crys- 
talline precipitate  with  bromine  is  still  obtained  in  solutions  of  phenol 
diluted  to  the  proportion  1 : 100,000.  In  separating  small  quantities 
of  phenol  from  animal  matter,  Jacobson  obtained  amorphous  precipi- 
tates with  bromine,  which,  after  drying,  dissolving  in  alcohol  and 
evaporating  slowly,  yielded  the  characteristic  groups  of  needles. 
Minute  quantities  of  phenol  are  best  dissolved  in  little  water,  and 
then  exposed  to  bromine  vapors. 
Detection  of  Thalline. — Blumenbach  found  that  thalline  is  not,  or 
only  in  traces,  taken  up,  by  agitating  acidulated  aqueous  solutions 
with  benzin,  benzol,  chloroform  or  ether,  but  is  dissolved  from  am- 
moniacal  liquids  by  these  solvents,  however  only  sparingly  by  petroleum 
benzin.  Distinct  reactions  could  be  obtained  by  this  treatment  with 
0.001  gm.  of  thalline  in  100  ccm.  of  urine ;  from  a  similar  amount 
of  blood  or  food-mixture  the  reactions  were  faint,  but  with  0.005  gm. 
were  distinct.  The  green  color  produced  by  ferric  chloride  is  distinct 
