2$  Mr.  hunter  on  the  Heat , &c* 
ball  of  the  thermometer  being  introduced  both  into  the 
flomach  and  redtum,  the  quickfilver  rofe  to  550.  Thefe 
experiments  were  repeated  with  nearly ‘the  famefuccefs. 
To  determine  whether  life  had  any  power  of  refilling 
heat  and  cold  in  thefe  claffes  of  animals,  I made  compa- 
rative trials  between  living  and  dead  ones. 
exp.  xxxviii.  I took  a living  and  a dead  tench,  and  a 
living  and  a dead  eel,  and  put  them  into  warm  water; 
they  all  received  heat  equally  fall;  and  when  they  were 
put  into  the  cold,  both  the  living  and  the  dead  received* 
it  equally- 
I long  fufpedted,  that  the  principle  of  life  was  not: 
wholly  confined  to  animals,  or  animal  fubftance  en- 
dowed with  vifible  organization  and  fpontaneous  mo- 
tion; but  I conceived,  that  the  fame  principle  exifted  in 
animal  fubftances,  devoid  of  apparent  organization  and 
motion,  where  the  power  of  prefervation  limply  was 
required. 
I was  led  to  this  notion  twenty  years  ago,  when  I was 
making  drawings  of  the  growth  of  the  chick  in  the  pro- 
cefs  of  incubation.  I then  obferved,  that  whenever  an 
egg  was  hatched,  the  yolk  (which  is  not  diminilhed  in  the 
time  of  incubation)  was  always  perfectly  fweet  to  the  very 
laft;  and  that  part  of  the  albumen,  which  is  not  expended 
on  the  growth  of  the  animal,  feme  days  before  hatching* 
a 
was 
