2 1 8 Dr.  white’s  Experiments 
exp.  xxvi.  The  fame  quantity  of  loamy,  vegetable 
earth,  out  of  my  garden,  and  brought  to  the  confiftence 
of  thick,  mud  by  addition  of  water,  was  next  tried.  The 
air  was  found  but  little  worfe;  in  one  inftance  only  di- 
minifhed  from  590  to  550;  in  another,  from  64°  to  6i°. 
It  is  probable  from  hence,  that  fine  loamy  vegetable 
earth  contains  little  putrefcent  matter,  as  it  gives  little 
noxious  effluvia.  The  addition  of  animal  and  other  kinds 
of  manures  will  much  vary  their  effects  in  this  refpedt. 
exp.  xxvii.  A mafs  of  the  fame  confiftence  was  formed 
of  pure  clay  and  water,  the  other  circumftances  of  the 
experiment  being  the  fame.  The  air  was  not  found  the 
worfe  by  it  in  fix  trials : in  one  there  was  only  the  fmall 
difference  of  6a°  to  6i°,  certainly  the  refult  of  fome 
flight  inaccuracy. 
So  that  the  pure  clay  foils  appear  to  be  favourable  to 
health;  they  emit  no  kind  of  feptic  or  noxious  effluvia. 
exp.  xxvni.  Wet  fand  was  tried  in  the  fame  manner, 
and  found  to  have  no  noxious  effecSt  upon  air:  from 
which  it  may  be  concluded,  that  the  general  notion  of 
the  falubrity  of  fandy  foils  is  founded  on  truth. 
I fhall  at  prefent  conclude  with  recapitulating  a few 
inferences,  which  feem  to  be  proved  by  the  preceding 
experiments. 
1 . The  atmofpheric  air  is  rendered  worfe  by  a long 
continuance  of  dry  weather. 
It 
