Am.  Jour.  Pharm.  j 
February,  19 19. 
Current  Literature. 
of  males.  In  other  words,  the  corpuscles  contain  from  five  and  a 
half  to  ten  times  as  much  creatin  as  creatinin,  while  in  the  plasma  it 
is  the  latter  that  is  predominant. 
The  Toronto  investigators  point  out  that  the  blood  creatinin  is 
apt  to  be  lower  in  females  than  in  males,  and  lower  in  subjects  de- 
prived of  exercise  than  in  those  leading  an  active  life.  It  is  sug- 
gested that  the  blood  creatinin  is  related  to  muscular  development 
in  much  the  same  way  as  the  creatinin  coefficient  of  the  urine.  We 
have  already  discussed  the  peculiar  occurrence  and  as  yet  unknown 
significance  of  creatin  in  the  urine.  Hunter  and  Campbell  have 
found  this  substance  present  at  times  in  the  blood.  They  state  that 
there  is  a  distinct  correspondence  between  increase  of  plasma  creatin 
and  the  appearance  of  creatin  in  the  urine ;  but  whether  the  plasma, 
in  the  absence  of  creatinuria,  is  creatin-free  or  whether  there  exists 
a  threshold  for  creatin  execretion  has  not  been  positively  determined. 
If  there  is  a  threshold,  it  is  a  very  low  one. 
CURRENT  LITERATURE. 
SCIENTIFIC  AND  TECHNICAL  ABSTRACTS. 
A  Rapid  Test  for  Occult  Blood. — The  benzidine  test  for  oc- 
cult blood  was  referred  to  in  these  pages  (1916,  p.  249),  when  the 
method  of  application  was  described  as  follows: 
To  about  5  Cc.  of  a  saturated  solution  of  benzidine  in  alcohol 
or  glacial  acetic  acid  an  equal  volume  of  3  per  cent,  hydrogen 
peroxide  solution  is  added,  and  then  one  Cc.  of  the  solution  to  be 
tested.  If  the  mixture  is  not  acid,  it  is  made  acid  with  acetic  acid. 
A  green  or  blue  color  indicates  the  presence  of  blood.  A  control 
test  in  which  water  is  substituted  for  the  liquid  under  examination 
should  give  no  coloration.  The  test  is  said  to  detect  blood  in  a 
dilution  of  one  in  300,000. 
W.  T.  Vaughan  (Jour.  Lab.  and  Clin.  Med.,  191 7,  2,  437,  Mar.) 
gives  a  simple  modification  of  this  test  which  can  be  applied  by  any 
physician.  A  few  grains  of  powdered  benzidine  (as  much  as  will 
lie  on  a  knife-point),  with  a  few  drops  of  glacial  acetic  acid  and 
a  few  drops  of  hydrogen  peroxide,  are  mixed  with  a  small  portion 
of  solid  faeces  on  a  glass  slide:  a  greenish-blue  fading  color  is  posi- 
tive.   This  test,  he  concludes,  is  simple,  rapid  and  clean,  and  is  not 
