94  Analysis  of  the  Gastric  Contents.  {AFebvlfvyPimm 
succeeding  tests.  No  turbidity  or  precipitate  should  be  caused  by 
silver  nitrate  (absence  of  chloride) ;  nor  by  barium  chloride  (sul- 
phate), nor  by  hydrogen  sulphide  or  potassium  ferrocyanide  (metals), 
nor  by  ammonium  oxalate  (calcium). 
If  I  c.c  of  formaldehyde  solution  be  mixed  with  10  c.c.  of  iodine 
test  solution,  and  potassa  solution  added  until  the  solution  becomes 
colorless,  no  precipitate  should  be  formed,  nor  an  odor  of  iodoform 
developed  (absence  of  acetone). 
The  solution  should  be  kept  in  dark  amber-colored  bottles,  in  a, 
cool  place,  protected  from  light. 
The  writer  is  much  indebted  to  Prof.  Virgil  Coblentz,  in  whose 
laboratory  this  work  was  carried  on,  for  his  great  interest  in  these 
investigations,  and  many  valuable  suggestions  in  connection  with 
them. 
New  York  College  of  Pharmacy,  January,  1898. 
THE  CHEMICAL  ANALYSIS  OF  THE  GASTRIC  CON- 
TENTS.1 
I.  Method  of  Analysis  for  Use  in  Clinical  Work. 
II.  Record  of  the  Analyses  of  the  Gastric  Contents  of  Fifty  Healthy  Indi- 
viduals. 
By  Henry  F.  Hewes,  M.D., 
Assistant  in  Chemistry,  Harvard  Medical  School,  Boston. 
{Continued  from  page  4.4..) 
Lactic  acid  is  not  a  constituent  of  gastric  juice,  and  is  not  pro- 
duced in  the  stomach  during  the  course  of  the  normal  gastric  di- 
gestion.59- 60  Statements  contrary  to  this  are  found  in  many  of  the 
leading  text-books ;  but  the  truth  of  the  above  statement  has  been 
adequately  demonstrated  by  the  researches  of  Bidder  and  Schmidt, 
Rothschild,  Martius  and  Luttke,  Boas  and  others.59 
The  presence  of  this  acid,  therefore,  in  the  gastric  contents,  except 
in  the  amount  ingested  in  the  food  as  acid  or  salts,  is  of  pathologi- 
cal significance.60 
'From  Boston  Medical  and  Surgical  Journal,  December  2,  1897. 
59  Martius  u.  Luttke:  Magensaure  d.  Menschen,  have  proved  this  conclu- 
sively by  establishing  a  comparison  of  the  total  acidity  and  total  hydrochloric 
acid,  and  finding  that  they  coincide  or  run  parallel  throughout  digestion. 
00  Boas  :  Miinchen  med.  Woch.,  No.  43,  1893  ;  Zeit.  klin.  Med.,  1894. 
