I X94  1 
XIII.  Experiments  upon  Air,  and  the  effects  of  different 
hinds  .of  Effluvia  upon  it’,  made  at  York.  By  W. 
White,  M.  D.  F.  S.  A.  Communicated  by  John 
Fothergill,  M.  D.  F.  R.  S. 
Read  I'cb.  5,  Y | 1 jq  E experiments  of  which  the  follow. 
ing  are  only  a part,  and  which  I pur- 
pofe  at  my  leifure  to  purfue  farther,  were  originally 
xindertaken  with  the  defign  of  afeertaining  the  ftate  of 
the  common  atmofpheric  air  in  and  about  this  city.  But 
in  order  to  form  a juft  idea  of  this,  it  feemed  to  me  ne- 
ceffary  to  find,  by  exadt  experiments,  the  real  effedts  of 
the  different  kinds  of  effluvia  upon  air,  elpecially  fuch 
as  are  in  a natural  ftate  conftantly  mixing  with  the  at- 
mofphere,  and  to  the  effedts  of  which  all  refpiring  ani- 
mals are  conftantly  expofed ; fuch  are  thofe  from  animal 
and  vegetable  fubftances,  and  from  different  kinds  of 
foils.  As  the  refult  of  thofe  inquiries  appeared  to  me  not 
only  curious,  but  in  a medical  view  very  interefting,  I 
am  in  hopes  they  may  be  acceptable  to  the  Royal  So- 
ciety. 
2 
It 
