2g6 
threequarters  of  an  hour  and  an  hour.  They  return  to  the  question 
in  a  second  paper*  with  practically  identical  results:  — 
Centrifuged  blood  ...  lOO’OO  %  successes  (12  cases) 
Gland  juice  .  91 '46  %  „ 
Cerebro-spinal  fluid  ...  26'3i  %  ,) 
Finger  blood  ...  ...  36’66  %  „ 
There  is  rather  a  remarkable  falling  off  in  the  blood  examinations  in 
their  ‘suspected’  cases,  per  cent.,  as  compared  with  go'QO  per 
cent,  for  gland  puncture.  They  conclude,  however,  that  their  results 
are  practically  the  same  as  those  of  Dutton  and  Todd,  and  that  while 
gland  puncture  is  the  best  method  to  employ  in  travelling,  the 
examination  of  the  blood  must  be  practised  in  treatment. 
Our  results  from  the  direct  examination  of  the  peripheral  blood 
(fairly  thick  fresh  preparations,  using  f "  square  cover  glasses,  Zeiss  D 
objective,  and  No.  4  eyepiece)  agree  with  those  of  Thiroux,  Wurtz 
and  Teppaz.t  that  is,  in  ten  cases  trypanosomes  were  not  seen.  Only 
a  single  examination  was  made  in  each  case,  however,  and  the  number 
is  too  small  for  any  exact  deductions. 
In  considering  the  efficiency  of  gland  palpation,  it  is  essential  to 
know  with  what  degree  of  certainty  one  may  depend  upon  finding 
the  trypanosomes  in  cases  of  the  disease,  at  any  or  every  examination, 
Gray  and  Tullochj:  say  that  ‘  trypanosomes  are  constantly  present  in 
the  lymphatic  glands  of  early  .  .  .  cases  .  .  .  and  can  be 
found  on  any  day  .  .  .  .’  Koch  also,  as  we  have  said,  points  out 
much  the  same  thing. 
If  we  were  dealing  with  known  cases  of  the  disease,  it  might  be 
concluded  that  centrifugation  of  the  blood  is  the  most  efficient  means 
of  diagnosis,  though  it  must  be  said  that  the  number  of  cases  on 
which  this  conclusion  would  be  based  is  rather  small. 
In  any  one  of  the  methods  there  is  naturally  an  appreciable 
margin  for  error,  and  not  only  so,  but  the  thoroughness  with  which  they 
are  practised  will  affect  the  result  to  a  great  degree.  When  we  come 
to  deal  with  a  country  in  which  the  disease  is  not  endemic  and  in 
which  the  examination  of  large  numbers  of  natives  is  involved,  and 
♦  Martin  and  Leboeuf,  1908,  Bull.  Soc.  path,  exot.,  T.  I,  No.  8. 
t  Thiroux,  Wurtz  and  Teppaz,  1908,  Bull.  Soc.  path,  exot.,  T.  I,  No.  5- 
t  Gray  and  Tulloch,  1907,  Roy.  Soc.  Sleeping  Sickness  Reports.  No.  VIII. 
