30  Analysis  of  the  Gastric  Contents.  {K™£™^m*' 
This  meal  thus  contains  the  various  nutritious  ingredients,  albu- 
minoids, starches,  sugars,  plant  albumins,  salts  and  fat. 
The  Leube  meal  consists  of  400  grammes  of  soup,  barley  or  flour 
soup,  60  grammes  scraped  beef,  50  grammes  of  wheat  bread,  and 
200  c.c.  of  water. 
The  use  of  both  these  meals  may  be  necessary — in  some  cases 
one,  in  some  the  other,  in  some  both.  In  a  majority  of  cases,  how- 
ever, but  one  meal  has  to  be  resorted  to  •  and  for  this  general  work 
the  Ewald  meal  is  the  superior.  This  superiority  of  the  Ewald  meal 
is  based  upon  the  following  comparative  data  : 
(1)  The  Ewald  meal  contains  lactic  acid,  if  at  all,  in  amounts  too 
small  to  react  to  the  ordinary  approved  tests.25  The  Leube  meal,  on 
the  other  hand,  contains  a  considerable  amount  of  lactic  acid.26 
As  the  production  of  lactic  acid  in  the  stomach  is  a  symptom  of 
pathological  conditions,  we  have  thus,  in  the  presence  of  this  acid 
after  the  Ewald  meal,  positive  evidence  of  abnormal  conditions,  which 
evidence  cannot  be  obtained  by  the  use  of  the  Leube  meal. 
(2)  The  quantitative  results  in  regard  to  the  amount  of  the  hydro- 
chloric acid  secreted  and  the  period  of  the  appearance  of  the  free 
hydrochloric  acid  vary  within  much  more  extended  limits  in  the 
normal  after  a  Leube  meal  than  after  an  Ewald.27, 28 
The  considerable  amounts  of  organic  acids  and  acid  salts  which 
may  be  present  in  the  Leube  meal  make  rough  estimations  of  the 
hydrochloric  acid  less  reliable  and  accurate  estimations  more  labor- 
ious than  with  the  Ewald  meal,  with  its  insignificant  amount  of  these 
substances. 
A  fourth  advantage  of  the  Ewald  meal  lies  in  the  fact  that  it  can 
be  taken  by  patients  with  disordered  digestive  functions  with  much 
less  difficulty  than  the  Leube. 
It  is  true  that  the  Ewald  meal  is  not  as  strong  a  test  of  the  diges- 
2  5  The  finding  of  lactic  acid  in  the  normal  contents,  as  reported  in  many 
cases  by  old  methods,  is  of  no  account,  as  the  methods  have  been  proven  inac- 
curate ;  Rosenheim  :  Zeit.  klin.  Med.,  Bd.  XXVIII,  1895. 
De  Jong  :  Archiv.  Verdauungskrankheiten,  Bd.  II,  H.  1. 
Laugruth  :  Archiv.  Verdauungskrankheiten,  Bd.  I,  s.  305. 
2  fi  Langruth  :  Loc.  cit. 
Rosenheim  :  Pathologie  u.  Therapie — Speiserohre  in  Magenskrankheiten. 
28  Einhorn  :  Berlin,  klin.  Woch.y  1888,  No.  32.  In  a  series  of  investigations 
of  the  normal  digestion  with  both  the  Ewald  and  Leube  meals,  found  the  results 
obtained  by  the  Kwald  meal  much  more  constant. 
