354 
On  the  Power  of  Soils  to  absorb  Manure. 
stance,  the  clay,  it  yet  may  possess  a greater  power,  weight  for 
weight,  than  the  pure  clay  itself. 
The  following  experiment  is  of  interest,  as  showing  that  the 
power  of  clay  to  absorb  ammonia  is  not  due  to  free  alumina  or  to 
any  other  substances  which  are  soluble  in  acids. 
The  white  pottery  clay  was  boiled  for  two  hours  in  strong 
hydrochloric  acid,  the  acid  being  further  left  in  contact  with  it 
for  twenty -four  hours,  at  the  expiration  of  which  time  the  clav 
was  frequently  washed  with  pure  water  till  all  trace  of  the  acid 
was  removed  : the  clay  was  then  dried. 
Experiment  79. — Muriate  of  ammonia  and  acid-treated  clay : — 
Standard  Solution  of  Muriate  of  Ammonia  4000  grains 
Acid-treated  Clay  .......  2000  , , 
Powdered  Cbalk 200  , , 
Digested  together  for  two 
hours. 
1st  Distillation  of  the  resulting  solution — 
Grains. 
Platinum  Salt. 
Ammonia. 
Per  Cent. 
229*48 
gave 
6*49  = 
•4947  or 
•2156 
2nd  Distillation — 
276-38 
gave 
ii 
•5908  or 
•2137 
1st  Analysis -2156  per  Cent. 
2nd  -2137  ,, 
Mean  ....  *2146  , , 
100  grains  of  t lie  original  solution  contained  . *3060  grains  of  Ammonia. 
100  grains  of  the  resulting  solution  contained  . -2146  ,,  ., 
Loss  by  100  grains  ....  -0914  ,,  ,, 
The  whole  quantity  (4000  grains)  will  therefore  have  lost  3 ’056  grains 
of  ammonia,  which  has  been  absorbed  by  2000  grains  of  clay,  making  the 
absorption  1*828  per  cent. 
The  absorptive  power  of  the  clay  in  its  natural  state  was  *2010, 
so  that  by  boiling  in  a strong  acid  we  have  caused  only  a very 
slight  diminution  of  this  power.  Chalk  was  added  to  the  ma- 
terials in  this  experiment,  in  case  the  treatment  with  acid  should 
so  far  have  removed  the  lime  as  to  destroy  the  power  of  the  clay 
to  decompose  the  salts  of  ammonia. 
Another  experiment  tvas  made  with  - this  acid-treated  clay  and 
muriate  of  ammonia,  icithout  the  addition  of  chalk. 
Experiment  80. — Acid-treated  clay  and  muriate  of  ammonia : — 
Muriate  of  Ammonia 4000  grains  1 » . , 
Acid-heated  Clay 2000  %,  } Dusted  for  two  hours. 
1st  Distillation  of  the  resulting  liquid — 
Grains. 
Platinum  Salt. 
Ammonia. 
Per  Cent. 
250-99 
gave  8*03  = 
•6122  or 
•2439 
2nd  Distillation — 
219-09 
gave  7*958  = 
•6061  or 
•2433 
