Am.  Jour.  Pharm.  \ 
Aug.,  1886.  J 
Hydroquinone  and  Arbutin. 
385 
HYDROQUINONE  AND  ARBUTIN. 
By  Hugo  Laueentz,  M.  D. 
Abstract  of  an  Inaugural  Dissertation,  University  of  Dorpat,  1886,  communicated  by  the 
author. 
The  primary  object  of  the  author's  investigations  was  the  detection 
of  the  two  substances  named,  in  the  animal  tissues  and  excretions,  and 
a  number  of  experiments  were  therefore  made  with  the  view  of  find- 
ing characteristic  tests.  The  color  reactions  of  hydroquinone,  obtained 
after  evaporating  the  alcoholic  solution,  are  as  follows  :  Froehde's  re- 
agent, violet  color,  becoming  darker  and  gradually  green  from  the 
margin.  Bromine  vapors  to  the  moist  residue  gray,  under  the  micro- 
scope showing  stellate  or  fascicular  needles  of  a  blackish  color  with 
green  hue,  and  becoming  intensely  green  with  ammonia,  quickly  chang- 
ing to  brown.  Chlorine  vapors  or  chlorine  water,  like  the  preceding, 
but  the  green  color  with  ammonia  less  bright.  The  same  behavior 
was  also  shown  with  dilute  solutions  of  bromine  in  potassium  bro- 
mide, and  of  iodine  in  potassium  iodide.  Chlorinated  lime  solution 
forms  at  once  dark  green  crystals  of  green  hydroquinone,  becoming 
brown  and  dissolving  in  excess  of  reagent  colorless.  Silver  nitrate 
warmed,  black  precipitate  and  characteristic  pungent  odor  of  quinone 
somewhat  resembling  that  of  iodine.  Ferric  chloride,  at  first  green 
hydroquinone,  and  with  more  of  the  reagent  quinone.  All  these 
reactions  are  observed  with  O02  mgm.  of  hydroquinone,  and  several 
other  less  characteristic  or  less  delicate  reactions  are  described  by  the 
author. 
Hydroquinone  was  next  mixed  with  urine,  blood  and  other  organic 
matters,  from  which  after  acidulation  with  sulphuric  acid  it  was  not 
dissolved  by  petroleum  benzin,  but  was  taken  up  by  benzol,  chloro- 
form, ether  and  acetic  ether,  the  residues  left  by  the  evaporation  of  the 
latter  yielding  the  color  reactions  most  distinct.  The  urine  passed  within 
twelve  hours,  after  having  taken  Ol  gm.  hydroquinone,  yielded  enough 
residue  to  give  slight  reactions  with  Freehde's  reagent.  On  increasing 
the  dose  to  0*15  gm.  reactions  were  also  obtained  with  ferric  chloride 
(odor  of  quinone)  and  with  silver  nitrate ;  but  chlorine  water  and  am- 
monia gave  yellow  or  brown  color.  The  urine  was  now  boiled  with  1 
per  cent,  sulphuric  acid,  agitated  with  acetic  ether,  the  residue  of  evap- 
oration boiled  with  sulphurous  acid,  again  shaken  with  acetic  ether  and 
