On  the  Absorbent.  Power  of  Soils. 
69 
formation)  was  placed  in  two  of  the  percolators,  forming  in  each 
a column  6 inches  deep.  They  were  labelled  A and  B.  The 
soil  was  moist,  hut  not  wet.  Ten  grains  of  sulphate  of  ammonia 
dissolved  in  ten  drams  of  distilled  water  were  intimately  mixed 
with  the  soil  (A).  Ten  grains  of  sesquicarbonate  of  ammonia 
were  similarly  mixed  with  (B). 
We  now  had  before  us  two  portions  of  soil,  one  of  which  repre- 
sented land  highly  manured  with  sesquicarbonate  of  ammonia  ; a 
salt  abounding  in  well-made  farmyard  manure,  and  forming  its  most 
valuable  ingredient.  The  other  represented  land  equally  highly 
dressed  with  that  salt  of  ammonia  which  is  formed  where  tanks 
or  manure  heaps  are  treated  with  sulphuric  acid,  gypsum,  &c. 
The  first  object  was  to  ascertain  the  effect  of  heavy  rain  falling  on 
land  thus  circumstanced  : accordingly  8 oz.  of  water  were  poured 
slowly  on  the  surface  of  both  A and  B.  These  8 oz.  formed  a 
column  3 inches  deep,  exceeding  therefore  in  amount  the  heaviest 
continuous  fall  of  rain  which  is  ordinarily  experienced  in  this 
country.  A considerable  portion  of  this  was  retained  by  the  soil, 
and  when  4 oz.  had  passed  through,  as  it  appeared  that  little 
more  was  likely  to  follow,  these  4 oz.  were  in  each  case  experi- 
mented on  as  follows  : — 
A.  Tested  with  reddened  litmus  and  found  to  be  alkaline, 
neutralized  with  sulphuric  acid,  evaporated  nearly  to  dryness, 
during  which  a large  flocculent  precipitate  was  formed  : precipi- 
tate and  filter  thoroughly  washed  with  dilute  alcohol : insoluble 
matter  remaining  on  the  filter  dried  and  heated  to  redness.  This 
weighed  4 grains,  and  proved  to  be  chiefly  gypsum.  The  portion 
of  the  precipitate  dissolved  by  the  alcohol  amounted  to  3 grains, 
of  which  2TV  grs.  sulphate  ammonia.  The  remaining  TV  gr.  were 
ascertained  to  be  sulphates;  but  as  the  inquiry  was  for  the  present 
confined  to  the  ammonia  question,  the  analysis  was  not  carried 
further. 
B.  The  first  4 oz.  which  passed  through  were  neutralized 
with  muriatic  acid  and  evaporated  : a very  slight  flocculent  preci- 
pitate showed  itself,  which  was  increased  on  adding  two  or  three 
drops  of  dilute  sulphuric  acid.  Treated  with  alcohol:  the  inso- 
luble matter  left  on  the  filter  weighed  1 gr.  (gypsum).  The 
alcoholic  solution  on  evaporation  left  4 grs.,  of  which  1^  were 
muriate  and  sulphate  of  ammonia.  These  results,  when  given  in 
a connected  form,  show  that — 
No.  1. 
Grains. 
B 
A gave  . . 
1 ‘3  muriate  and  sulphate 
and  sulphate  of  ammonia. 
