of  Animals  and  Vegetables.  39 
I imagined  I law  a material  difference  between  them  in 
their  power  of  fupporting  cold. 
From  obfervations  and  the  foregoing  experiments  it 
plainly  appears,  that  the  living  principle  will  not  allow 
the  heat  of  l'uch  animals  to  link  much  lower  than  the 
freezing  point,  although  the  furrounding  atmofphere  be 
much  colder,  and  that  in  fuch  a Hate  they  cannot  fup- 
port  life  long;  but  it  may  be  obferved,  that  molt  vege- 
tables of  every  country  can  fuftain  the  cold  of  their 
climate.  In  very  cold  regions,  as  in  the  more  Northern 
parts  of  America,  where  the  thermometer  is  often  5 o° 
below  o,  where  peoples  feet  are  known  to  freeze  and 
their  nofes  to  drop  off  if  great  care  be  not  taken,  yet  the 
fpruce-fir,  birch,  juniper,  See.  are  not  affected. 
Yet  that  vegetables  can  be  affedted  by  cold,  daily  expe- 
rience evinces ; for  the  vegetables  of  every  country  are 
affefted  if  the  feafon  be  more  than  ordinarily  cold  for 
that  country,  and  fome  more  than  others;  for  in  the 
cold  climates  abovementioned,  the  life  of  the  vegetable 
is  often  obliged  to  give  way  to  the  cold  of  the  country : 
a tree  fhall  die  by  the  cold,  then  freeze  and  fplit  into  a 
great  number  of  pieces,  and  in  fo  doing  produce  conii- 
derable  noife,  giving  loud  cracks  which  are  often  heard 
at  a great  diftance. 
In  this  country  the  fame  thing  fometimes  happens  to 
exotics  from  warmer  climates : a remarkable  inftance  of 
this 
