of  Animals  and  Vegetables . 29 
was  alfo  perfectly  fweet ; although  both  were  kept  in  a 
heat  of  1 o 30,  in  the  hen’s  egg  for  three  weeks,  and  in 
the  duck’s  for  four;  but  I obferved,  that  if  an  egg  was 
not  hatched,  that  egg  became  putrid  in  nearly  the  fame 
time  with  any  other  dead  animal  matter. 
To  determine  how  far  eggs  wduld  hand  other  tefts  of 
a living  principle,  I made  the  following  experiments. 
exp.  xxxix.  I put  an  egg  into  cold  at  about  o,  and 
froze  it,  then  allowed  it  to  thaw ; from  this  procefs  I con- 
ceived, that  the  preferving  powers  of  the  egg  muft  be 
loft.  I then  put  this  egg  into  the  cold  mixture,  and  with 
it  one  newly  laid;  and  the  difference  in  freezing  was 
feven  minutes  and  a half,  the  frefh  one  taking  fo  much 
longer  time  in  freezing. 
exp.  xl.  A new  laid  egg  was  put  into  a cold  atmo— 
fphere,  fludluating  between  170  and  1 5 0 ; it  took  above 
half  an  hour  to  freeze;  but,  when  thawed  and  put  into 
an  atmofphere  at  250,  it  froze  in  half  the  time..  This 
experiment  was  repeated  feveral  times,  with  nearly  the 
fame  fuccefs. 
To  determine  the  comparative  heat  between  a living 
and  a dead  egg,  and  alfo  to  determine  whether  a living 
egg  be  fubject  to  the  fame  laws  with  the  more  imperfect 
animals,  I made  the  following  experiments. 
EXP. 
