Population  and  Difeafes  of  Chefter.  143 
dent  that  1060  have  never  had  the  fmall  pox  out  of 
14713  inhabitants,  that  is  1 in  14. 
The  fadts  recorded  in  Table  iv.  feem  to  determine  the 
age  when  children  fhould  be  inoculated  in  order  to  fe- 
cure  the  greateft  poffible  benefit  to  mankind.  It  appears 
here,  that  under  one  month  old  not  one  died  of  the 
fmall-pox ; that,  under  fix  months  old  only  7 out  of 
202 ; and  yet  that  above  a quarter  of  the  whole  died 
under  one  year  old.  My  ingenious  friend  Dr.  percival 
firfl  difcovered  at  Manchefler  the  fatality  of  the  fmall- 
pox  in  early  infancy,  which  induced  him  with  much 
candour  and  good  fenfe  to  correct  a former  opinion  on 
this  fubjedt  founded  on  the  greater  fafety  of  inoculation 
in  children  a few  years  old.  Indeed,  where  children  can 
be  fecured  from  all  danger  of  the  natural  infection,  the 
greater  hazard  to  young  infants  from  inoculation  will  be 
a fufficient  reafon  to  defer  the  operation  for  three  or  four 
years.  The  fmall-pox  was  fatal  to  22  males  and  29  fe- 
males under  one  year  old,  that  is,  to  feven  more  females. 
This  fadt  confirms  what  Dr.  percival  obferved  at  Man- 
chefter.  The  epidemic  fmall-pox  began  near  the  fum- 
mer,  and  almoft  ended  at  the  winter  folftice,  only  19 
remaining  ill  of  the  difeafe  in  January  1775,  when  the 
general  furvey  was  taken. 
Dr. 
