Am.  Jour.  Pharm. 
June,  1892. 
The  Chemistry  of  the  Liver. 
323 
individual  lobules.  The  liver  is  a  very  vascular  organ,  and  is 
supplied  with  blood  from  two  different  sources  ;  from  one  source, 
by  means  of  the  hepatic  artery,  it  receives  blood  from  the  systematic 
circulation,  which  blood  is  intended  for  the  general  nutrition  of  its 
substance  ;  or,  in  other  words,  for  the  repair  of  the  wear  and  tear  of 
its  tissues ;  from  another  source,  by  means  of  the  portal  vein,  it 
receives  blood  from  the  digestive  viscera,  notably  from  the  stomach 
and  intestines,  and  in  this  portal  blood  are  conveyed  to  the  liver 
the  dissolved  products  resulting  from  the  action  of  the  various 
digestive  juices  on  the  constituents  of  food  during  their  passage 
through  the  alimentary  canal ;  these  soluble  products  which  result 
from  the  processes  of  digestion  are  in  the  liver  submitted  to 
important  chemical  changes,  and  these  changes  I  propose  to  con- 
sider to-night.  To  recapitulate,  the  hepatic  artery  merely  conveys 
arterial  blood  for  the  nutrition  of  the  liver  substance,  whereas  the 
portal  vein,  by  means  of  its  tributaries  from  the  digestive  viscera, 
conveys  in  its  blood  material  upon  which  the  liver  exercises  its 
elaborative  action. 
The  substances  elaborated  within  the  liver  can  leave  that  organ 
by  two  channels,  either  being  discharged  by  means  of  the  bile-duct 
into  the  upper  part  of  the  intestines,  or  passing  by  means  of  the 
hepatic  vein  into  the  general  circulation.  The  liver  is  therefore 
placed  in  the  road  by  which  portal  blood  conveying  material  from 
the  digestive  tract  must  pass  before  it  can  gain  access  to  the 
general  circulation,  and  it  is  a  gland  provided  with  remarkable 
chemical  powers,  by  means  of  which  it  can  transform  substances 
that  would  in  themselves  be  harmful  to  the  organism  into  useful  or 
harmless  products.  We  have  now  to  consider  what  these  chemical 
powers  are,  with  which  the  liver  is  provided. 
The  chief  chemical  functions  of  the  liver  are,  the  secretion  of 
bile,  the  formation  of  sugar,  the  formation  of  urea  and  other  urinary 
substances.  As  regards  the  first-mentioned  function,  viz.,  the 
secretion  of  bile,  the  liver  performs  the  role  of  a  secreting  gland, 
the  duct  of  which,  viz.,  the  bile-duct,  opens  into  the  upper  part  of 
the  intestines.  As  regards  the  two  other  functions,  viz.,  the 
formation  of  sugar,  urea  and  other  urinary  substances,  the  liver  is 
practically  playing  the  part  of  a  ductless  gland,  from  which  the 
elaborated  products  (sugar,  urea,  etc.)  are  carried  off  by  the 
outgoing  venous  blood.    Bile  is  a  somewhat  viscid  fluid,  dirty 
