AFebJruaryP?9aor2m'}         Animal  Digestive  Ferments.  55. 
ity  of  the  suppurated  matter,  and  to  obtain  a  speedy  cicatrization.'" 
Carminati,  a  celebrated  professor  of  medicine  and  surgery  at 
Pavia,  to  whose  notice  these  investigations  were  brought  by  Spal- 
lanzani,  likewise  used  the  gastric  juice  of  animals  as  topical  appli- 
cations, and  also  used  it  internally  in  cases  of  indigestion,  etc.,  with 
equally  good  results — the  first  recorded  therapeutic  use  of  a  digest- 
ive secretion. 
It  is  probably  due  to  the  absorbing  interest  manifested  for  the 
multitude  of  discoveries  in  all  branches  of  science,  more  particularly 
in  chemistry  (by  Scheele,  Lavoisier,  Gay  Lussac,  Berzelius  and 
others),  at  the  close  of  the  eighteenth  and  the  early  part  of  the 
nineteenth  century;  probably  also  to  the  disturbed  social  and; 
political  conditions  incidental  to  the  Napoleonic  wars,  that  the 
researches  of  Spallanzani  did  not  become  generally  known.  Then, 
again,  the  difficulty  of  the  subject,  the  crudeness  of  existing  meth- 
ods, the  want  of  exact  instruments  and  appliances,  may  account  for 
the  conflicting  opinions  and  theories,  for  the  cessation  of  marked 
progress  in  the  physiology  of  digestion,  up  to  183  I.  It  was  about 
this  time  (1828)  that  a  discovery  of  the  utmost  importance  in 
chemistry,  the  breaking  down  of  the  barrier  between  organic  and 
inorganic  chemistry,  the  destruction  of  the  idea  of  the  existence  of 
a  "  life  "  force  peculiar  to  organic  bodies,  viz.,  the  synthesis  of  urea, 
was  made  by  Wohler.  This  may  well  be  conceived  to  have  given 
a  fresh  impulse  and  promise  to  the  isolation  of  some  of  the  princi- 
ples concerned  in  vital  action,  and  thus  to  the  study  of  the 
physiology  of  digestion,  for  the  most  important  advances  follow 
close  on  this  time. 
In  1824  by  Prout — and  independently  by  Thiedemann  and  Gmelirt 
in  1826 — free  hydrochloric  acid  was  found  in  gastric  juice,  and 
believed  by  the  latter  to  be  the  digestive  principle. 
Luechs  discovered,  in  183 1,  the  power  of  saliva  to  dissolve  starch 
and  convert  it  into  reducing  sugar ;  later  Schwann,  Mialhe  and 
Cohnheim  corroborated  the  statement  and  precipitated  the  active 
principle  by  various  methods. 
In  1834,  the  publication  of  the  results  of  Beaumont's  observations 
of  natural  digestion  in  the  human  stomach — in  a  case  of  a  traumatic 
fistula — terminated  the  discussion  regarding  the  existence,  activity 
and  acidity  of  gastric  juice.  Beaumont,  however,  advanced  the 
theory  of  the  combination  of  the  juice  with  the  food  to  form 
