Am.  Jour.  Pharm.) 
Aug.,  1885.  J 
The  Tests  for  Bile  in  Urine. 
409 
The  camphor-free  oil  is  used  in  Japan  chiefly  as  an  illuminant  by 
the  lower  classes^  also  for  the  preparation  of  carbon  for  "  Chinese  Ink/' 
and  Mr.  Oishi  indicates  a  use  for  it  as  a  constituent  of  varnishes.^  It 
is  questionable^  however,  if  it  can  be  called  an  efficient  substitute  for 
the  popular  camphorated  oil  of  this  country,  and  I  cannot  conceive 
how  it  is  destined  to  replace  it.  The  crude  oil  might  possibly  be  a 
valuable  addition  to  our  materia  medica,  but  I  am  afraid  that  its 
sassafras  odor  would  prevent  the  public  taking  it  up. 
From  the  United  States  we  hear  that  large  quantities  of  this  oil  are 
being  received  there,  and  that  it  is  being  used  for  adulterating  oil  of 
wintergreen.  There  should  be  no  difficulty  in  detecting  the  adultera- 
tion, for  oil  of  wintergreen  has  a  specific  gravity  of  1*180,  which  the 
addition  of  camphor  oil  will  lower.  A  rough  and  ready  test  (perhaps 
as  good  as  any)  is  to  gently  agitate  a  few  drops  of  the  oil  in  water ; 
if  it  be  pure  it  wholly  subsides  in  a  few  seconds,  but  if  it  contains  cam- 
phor oil  several  minutes  elapse  before  it  subsides,  and  time  is  given  to 
notice  that  the  particles  of  oil  assume  different  forms  other  than  globular. 
The  action  of  nitric  acid  may  also  be  noted  ;  it  has  little  effect  upon 
pure  oil,  but  adulterated  oil  becomes  red. — Phar.  Jour,  and  Trans., 
June  20,  p.  1045. 
The  Tests  for  Bile  in  Urine  have  been  critically  examined  by 
Carl  Deubner  (Thesis,  Dorpat,  1884),  who  obtained  the  best  results 
with  the  methods  proposed  by  Hilger  and  by  Rosenbach.  According 
to  Hilger  (^'Archiv  d.  Phar.,  vol.  206,  p.  385)  the  urine  is  moderately 
heated  and  rendered  alkaline  by  barium  hydrate;  a  small  portion  of  the 
washed  precipitate  treated  carefully  with  a  few  drops  of  concentrated 
nitric  acid  gives  the  well-known  color  reactions,  green,  violet,  blue. 
Rosenbach  (''Chem.  Centralblatt,''  1876,  p.  150)  recommends  filter- 
ing the  urine  through  white  filter  paper;  this  acquires  a  yellow  or 
brown  color,  which  with  a  drop  of  nitric  acid  changes  to  yellowish  red, 
the  margin  of  the  spot  becoming  violet  and  deep  blue,  while  towards 
the  centre  the  color  gradually  changes  to  emerald  green.  The  modifi- 
cation of  this  test  recommended  by  Deubner  consists  in  placing  a  few 
drops  of  the  urine  upon  a  porous  plate  of  white  clay,  when  the  spot 
remaining  will  show  the  reaction  plainly  and  for  some  time.  The 
advantage  of  this  modification  is  that  very  little  of  the  material  is  suf- 
ficient for  a})plying  the  test,  and  that  errors  arising  from  the  decom- 
position of  the  paper  by  the  acid  are  excluded. 
^  When  the  oil  is  rubbed  on  the  skin  a  resinous  coating  remains  on  dry- 
ing.   This  is  rather  objectionable  than  otherwise. 
