Am.  Jour.  Pharm.  1 
Dec,  1886.  f 
Tests  for  Albumin  in  Urine. 
60? 
papers  are  less  satisfactory,  as  an  inconvenient  quantity  has  to  be  used. 
The  two  first  named  papers  require  the  use  of  citric  acid  in  the  cold, 
which  involves  a  possible  fallacy,  in  that  citric  acid  produces  a  precip- 
itate when  an  excess  of  soluble  urate  is  present  in  the  urine.  Urine 
of  high  specific  gravity  should  consequently  be  diluted,  to  avoid  this 
source  of  error ;  and  sufficient  acid  must  be  added  to  render  neutral 
or  alkaline  urine  distinctly  acid.  The  potassio-mercuric-iodide  papers 
appear  to  precipitate  all  albumins  indiscriminately ;  but  the  precipi- 
tates with  artificial  peptones  are  dissolved  on  heating,  and  reappear  on 
cooling.  The  ferrocyanide  papers  do  not  precipitate  artificial  peptones ;; 
while  their  reaction  with  other  albumins  is  keen.  One  apparent  fallacy 
that  might  occur  in  the  use  of  Dr.  Oliver's  papers  is  not  noticed  in  the 
report.  It  happened  to  us  once,  in  employing  an  iodide  paper  to  test 
some  serum  drawn  from  a  hydrocele,  to  find  that  the  paper  gave  ap- 
parently no  reaction,  whereas  the  liquid  when  boiled  in  another  tube, 
became  quite  solid.  Upon  taking  the  paper  from  the  first  portion  of 
the  liquid,  however,  on  examining  it  more  carefully,  it  wTas  found  to  be 
ooated  completely  with  a  thick  layer  of  solid  albumin,  which  had 
apparently  prevented  any  further  egress  of  the  salt  from  the  paper 
into  the  liquid  around,  in  that  way  frustrating  all  further  reaction. 
The  very  sensitiveness  of  the  test  induced  a  belief  in  its  failure. 
When,  however,  the  serum  was  well  diluted  with  water,  the  albuminous 
nature  of  the  liquid  was  at  once  completely  demonstrated  by  the  paper. 
It  is,  perhaps,  possible  that  the  same  thing  might  occur  in  a  specimen 
of  extremely  albuminous  urine. 
2.  Dr.  Pavy's  pellets  of  nitric  acid  and  ferrocyanide  of  potassium 
are  reported  to  give  as  good  results  as  the  potassio-mercuric  papers  of 
Dr.  Oliver,  (neither  of  these  reagents  being  quite  so  searching  as  the 
solution  of  the  potassio-mercuric  iodide).  They  are  stated  not  to  pre- 
cipitate peptones ;  and,  therefore,  in  conjunction  with  the  iodide  solu- 
tion, they  may  distinguish  the  two  kinds  of  proteid,  and,  so  far,  help 
in  the  clinical  analysis  of  pathological  conditions.  In  using  this  test, 
citric  acid  has  to  be  first  added  ;  and  this  source  of  fallacy  (as  noted 
above)  must  be  avoided  by  dilution,  where  the  specific  gravity  of  the 
urine  is  high.  Bubbles  of  gas,  which  the  pellets  sometimes  liberate, 
must  also  be  distinguished  from  a  precipitate. 
3.  Dr.  Johnson's  picric  acid  solution  requires  decided  excess  of  the 
jre-agent,  or  the  addition  of  acetic  or  citric  acid.  It  is  reported  to  be 
most  useful,  giving  reactions  only  second  to  those  of  the  potassio- 
