A  half-pint  tumbler  of  whisky,  which  has  been  diluted  with
three  times  its  volume  of  water,  will  still  contain  about
i  J  fluid  ounces  of  pure  alcohol,  and  the  percentage  of  alcohol
will  still  be  higher  than  that  found  in  the  majority  of  wines,
except  port  wine.
These  figures  are  of  some  importance  because  the  numerous
experiments  which  have  been  carried  out  recently,  and  which
will  be  considered  below,  are  almost  entirely  based  on  cubic
centimetres  of  pure  alcohol  and  not  on  fluid  ounces  of  wine.
It  would  be  quite  impossible  in  a  work  of  this  kind  to
make  any  attempt  whatever  to  give  an  account  of  the  im-
mense mass  of  work  which  has  been  done  on  the  subject  of
alcohol  taken  as  a  beverage.  Although  the  investigations
are  apparently  simple,  there  are  many  pitfalls.  For  instance,
it  is  well  known  that  some  people  are  more  susceptible  to
alcohol  than  others ;  again,  a  considerable  amount  of  toler-
ance is  established  by  those  who  habitually  take  alcoholic
drinks,  so  that  experiments  conducted  upon  two  individuals
may  not  produce  the  same  effect.  Then  there  is  the  further
question  of  the  test  to  be  employed,  and  the  standard  to  be
used,  in  determining  the  effect  of  taking  alcohol.  The
difficulties  will  probably  be  more  readily  appreciated  by
considering  the  action  of  alcohol  on  the  body.  Taken  into
the  stomach,  the  general  effect  of  alcohol  is  to  produce  an
initial  stimulus  to  the  heart  and  to  cause  a  dilatation  of  the
vessels  of  the  skin  :  this  last  appears  to  be  a  specific  action.
