Thus  Mr.  Gunn  has  found  that  females  are  much
more  liable  to  vomit  after  anaesthetics  than  males;  of
about  2000  males  and  nearly  2000  females  who  were
anaesthetised  at  Moorfields  Ophthalmic  Hospital  51
per  cent,  of  the  females  and  40  per  cent,  of  the  males
were  sick;^  it  must  be  added  that  Dr.  Silk  finds
vomiting,  both  in  childhood  and  adult  age,  more
common  in  males,  though  he  also  finds  that  excessive
evolution  of  intestinal  flatulence  under  anaesthesia
occurs  almost  exclusively  among  women.  It  is  to
Dr.  Silk  that  we  owe  the  most  valuable  contribution
yet  made  to  the  precise  knowledge  of  sexual  differ-
ences as  revealed  by  anaesthetics.^  Of  his  1000  cases
240  were  in  men,  760  were  in  women;  the  average
age  in^each  sex  Was  24  years.  It  is  the  tendency  to
muscular  movement  which  may  be  most  easily
observed.  Rhythmic  movements,  such  as  swinging
the  legs,  beating  time  to  music  with  the  hands,  etc.,
were  observed  27  times;  it  is  impossible  to  say  in
what  class  of  patients  such  movements  are  to  be
expected;  6  (or  2.5  per  cent.)  of  Dr.  Silk's  male  cases
showed  such  movements;  21  (or  2.8  per  cent.)  of  the
female  cases.  The  excess  of  females  is  here  scarcely
perceptible;  it  is  much  more  marked  in  regard  to
rigid  muscular  contractions  of  an  opisthotonic
character;  they  were  noted  in  only  17  (or  7.1  per  cent.)
males,  but  in  89  (or  11.7  per  cent.)  females.  A
tendency  to  opisthotonos  was  observed  in  7  males
(or  2. 9  per  cent.)  and  in  44  females  (or  5.8  per  cent.).
^  J.  F.  W.  Silk,  Manual  of  Nit.  Ox.  AniBsthesia.
^  R.  Marcus  Gunn,  Brit.  Med.  Journal,  ]vL\y  21,  18S3.
