of  Animals  and  Vegetables.  43 
exp.  iv.  April  7th,  a cold  day,  wind  in  the  North, 
cloudy,  at  three  o’clock  in  the  afternoon,  the  thermome- 
ter in  the  tree  was  at  42,0,  the  atmofphere  at  420  alfo. 
exp.  v.  April  9th,  a cold  day,  with  fnow,  hail,  and 
wind,  in  the  North-call ; at  fix  in  the  evening  the  ther- 
mometer in  the  tree  at  450,  the  atmofphere  at  390. 
Here  the  tree  was  warmer  than  the  atmofphere,  juft 
as  might  have  been  expected.  If  thefe  experiments 
prove  any  thing,  it  is  that  there  is  no  ftandard;  and  pro- 
bably thefe  variations  arofe  from  fome  circumftance 
which  had  no  immediate  connection  with  the  internal 
powers  of  the  tree ; but  it  may  alfo  be  fuppofed  to  have 
arifen  from  a power  in  the  tree  to  produce  or  diminifh 
heat,  as  fome  of  them  were  in  oppofition  to  the  atmo- 
fphere. 
After  having  endeavoured  to  find  out  the  comparative 
heat  between  vegetables  and  the  atmofphere,  when  the 
vegetables  were  in  aftion ; I next  made  my  experiments 
upon  them  when  they  were  in  the  paffive  life. 
As  the  difference  was  very  little  when  in  their  moft 
adlive  ftate,  I could  expect  but  very  little  when  the 
powers  of  the  plant  were  at  reft. 
From  experiment  upon  the  more  imperfect  daffies  of 
animals  it  plainly  appears,  that  although  they  do  not 
refill  the  effiedls  of  extreme  cold  till  they  are  brought 
to  the  freezing  point,  they  then  appear  to  have  the 
G 2 power 
