on  Air,  See. 
203 
Flowers  of  Ulmaria  diminifhed  it  from  . 60  to  2 
Ten-weeks  flocks,  . , 60  to  1 
Leaves  of  Sage,  . . . . 6 1 to  9 
The  vegetables  were  at  the  end  equally  fweet  as  when 
firft  gathered  and  put  into  the  phial  of  air. 
Thefe  fadts  are  very  curious,  interefling,  and  con- 
vincing. It  is  amazing,  that  vegetables,  whilft  frefh  and 
free  from  the  lead:  degree  of  putrefcency,  fhould  have 
fuch  a noxious  tendency  as  to  fpoil  the  air,  and  render  it 
not  only  ufelefs  but  fatal  to  animal  life,  and  that  in  fo 
fhort  a time. 
We  have  here  a ftriking  example  of  the  neceffity  of 
faithful  experiments:  by  them  alone  we  can  add  cer- 
tainty to  fcience,  and  develop  nature  in  her  moll  fecret 
and  abflrufe  operations;  and  as  die  is  unchangeable  in 
herfelf,  every  difeovery  extorted  from  her  is  immutable. 
For  want  of  attention  to  this  laborious  but  foie  method 
of  coming  at  truth,  it  is  a pretty  general  opinion  in  the 
world,  that  even  rotten  vegetables  are  little  noxious : and 
a late  author,  whom  I only  mention  becaufe  his  book  is 
pretty  generally  read,  in  a chapter  upon  putrid  fevers 
and  infection,  exprelsly  fays : “ The  effluvia  of  rotten 
“ vegetable  matters  have  little  effedt  in  contaminating 
Vol.  LXVIII.  D d “ the 
