I  have  no  doubt,  therefore,  that  in  such  and  similar  cases,  the
exhalant  vessels  opening  upon  the  mucous  surface  of  the  stomach  and
intestines,  may  throw  out,  instead  of  their  normal  and  habitual  secre-
tions, either  gases  of  various  kinds,  or  a  fluid  whose  affinity  for  caloric
is  such  that  it  assumes,  as  soon  as  evolved,  the  gaseous  form.  But
this  subject  deserves  a  special  consideration,  which  will  detain  us  for
a  moment.
Pneumatosis — a  word  first  employed,  I  think,  by  Yogel,  properly
means  the  morbid  generation  of  air  or  gaseous  fluid.  Air  is  contained
normally  in  several  of  the  cavities  of  the  body,  as  the  trachea,  bronchi,
and  air  cells.  It  exits,  also,  in  the  stomach  and  bowels.  Abercrombie
says  they  are  collapsed  in  the  natural  state;  but  auscultation  and  per-
cussion prove  the  contrary,  and  the  escape  of  air  upwards  and  dosvn-
Avards  is  consistent  with  the  best  health.
