Am"o?tu!\S£arm'}  Gleanings  from  the  German  Journals.  491 
invert  sugar  in  cane  sugar  by  this  test.  Dr.  N.  Wender,  studying 
the  test  to  ascertain  its  applicability  to  the  examination  of  urine, 
found  that  a  number  of  urine  constituents  were  capable  of  decolor- 
izing strongly  alkaline  methylene  blue  solutions.  By  proper  dilu- 
tion of  the  urine  this  source  of  error  was  remedied,  and  the  test 
then  is  of  sufficient  accuracy  to  warrant  its  recommendation.  5-10 
cc.  urine  are  diluted  with  nine  volumes  of  distilled  water ;  1  cc.  of 
the  diluted  urine,  I  cc.  of  an  aqueous  methylene  blue  solution  (this 
solution  is  permanent  and  contains  one  gram  pure  color  in  a  liter),  1 
cc.  normal  potassium  hydrate  solution  and  2  cc.  distilled  water  are 
heated  and  retained  at  the  boiling  point  for  about  one  minute ;  if 
the  original  urine  contained  0-5  per  cent,  or  more  of  dextrose  the 
blue  color  will  be  discharged,  otherwise  the  urine  should  not  be 
pronounced  diabetic.  The  decolorized  test  upon  cooling  separates 
methylene  white,  and  by  exposure  to  air  this  gradually  absorbs 
oxygen  and  reproduces  the  blue  color.  From  quantitative  experi- 
ments made  with  glucose,  it  was  determined  that  to  decolorize  one 
molecule  methylene  blue  one  molecule  of  dextrose  was  required,  so 
that  one  milligram  of  pure  color  (equivalent  to  1  cc.  of  the  solu- 
tion), requires  0*5  milligram  of  dextrose.  A  number  of  experiments 
with  normal  urine  established  that  one  mg.  methylene  blue  was 
decolorized  by  about  4- 5  cc.  of  the  diluted  urine  (14-9)  indicating 
in  normal  urine  a  quantity  of  reducing  substances  equivalent  to 
oil  per  cent,  dextrose.  After  ascertaining  that  the  urine  is  diabetic, 
it  is  possible  to  approximately  estimate  the  dextrose  by  diluting 
with  49,  99  or  199  volumes  of  water,  accordingly  as  the  specific 
gravity  is  found  in  one  of  the  three  groups,  1 -017-1-025,  1-025-1-030, 
1-030-1-038;  by  a  series  of  trials  is  next  determined  the  exact  quan- 
tity of  the  diluted  urine  necessary  to  decolorize  one  cc.  of  the 
methylene  blue  solution ;  the  formula  0      v  (v  representing  the 
c 
dilution  of  the  urine  50,  100  or  200,  and  c  the  number  of  cc.  of  the 
diluted  urine  necessary  for  decolorization),  gives  at  once  the  per- 
centage of  dextrose  in  the  original  urine. — Pharm.  Post,  1893,  393- 
397. 
Lanolin. — E.  Dieterich,  in  the  Helfenberger  Annalen,  1 893  (through 
Pharm.  Post,  1893,  426),  publishes  the  observation  that  lanolin  is 
capable  of  becoming  rancid ;  a  decolorized  and  purified  sample  in 
1886  had  the  acidity  figure  of  0-84 ;  after  six  and  a  half  years'  keep- 
