The  profundity  of  the  crime  question  is  nowhere  hetter  illus-
trated than  in  the  relation  of  weather  to  crime. There  is  little
reason  to  doubt  that  thermometric  and  barometric  changes  exert
a  profoimd  influence  on  the  quantity  and  quality  of  cnmitial  acts
in  any  given  community. The  crime  wave,  especially  so  far  as
crimes  of  impulse  are  concerned,  has  a  curve  which  corresponds
fairly  well  with  the  temperature  curve. It  is  traditional  in  Spain
that  the  crime  wave  rises  when  the  east  wind  blows. Burglary
and  robbery,  especially  of  the  "  liold-up"  variety,  are  more  fre-
quent in  winter. Murder  and  suicide  occur  most  often  in  the
summer  nxniths. During  January,  February,  and  March  of


SOCIAL   PATHOLOGY  23

1901,  twelve  hundred  suicides  were  reported  in  the  United
States,  as  against  sixteen  hundred  during  July,  August,  and  Sep-
tember. In  the  same  periods  the  number  of  murders  was  seven-
teen hundred  for  the  cold,  and  two  thousand  five  hundred  for
the  hot  months. The  number  of  lynchings  in  the  hot  months  was
double  that  during  the  cold. The  hot  weather  increased  the  mur-
derous mob  instinct. Leffingwell  has  written  very  convincingly
on  the  relation  of  seasons  to  crime."

Hot  weather  seems  to  have  an  effect  chiefly  in  increasing
crimes  of  impulse. Neuropathic  individuals  adjust  themselves
with  great  difficulty  to  changes  of  ciimatic  environment. The
predisposition  to  crime  existing,  anything  that  destroys  the
already  unstable  mental  equilibrium,  and  at  the  same  time  makes
the  nervous  centres  hyperesthetic,  has  the  same  effect. Hot
weather  is  in  no  wise  different  in  this  respect  from  alcohol. In-
deed, the  greater  consumption  of  alcoiiolic  beverages  during  the
summer  months  is  inseparable  from  the  effects  of  the  weather
per  se. Auto-intoxication,  which,  as  will  be  noted  later,  I  believe
to  be  a  prominent  factor  in  the  etiology  of  crime,  is  in  some
subjects  more  marked  in  summer,  despite  the  increase  of  skin
activity,  because  of  a  relatively  great  increase  in  tissue  metamor-
phosis that  over-balances  elimination. The  effect  of  direct  sun-
rays  upon  neuropaths  is  well  known. Sunstroke  and  subsequent
criminality  by  impulse  is  not  rare. The  increase  of  robbery  dur-
ing the  winter  months  is  due,  not  to  the  effect  of  temperature
upon  criminal  neuropathy,  but  to  the  increased  necessities,  both
of  the  criminal  and  the  working  class. 