244  Annual  Report  of  the  Consulting  Chemist  for  1882. 
Bats’  guano  varies  much  in  composition,  and  consequently 
may  be  Worth  11/.  to  12/.  a ton,  or  only  5/.  to  6/.  a ton. 
The  sample  to  which  the  preceding  analysis  refers  would  not 
be  dear  at  11/.  a ton  ; for  it  is  a manure  which  is  rich  in  ready- 
formed  ammonia  and  nitrogenous  organic  matter,  which  are 
readily  decomposed  in  the  soil. 
In  addition  to  the  nitrogenous  organic  matters  and  salts  of 
ammonia,  capable  of  yielding  together  12  per  cent,  of  ammonia, 
this  bats’-dung  contains  some  nitrate  of  potash  and  soda,  and  an 
amount  of  soluble  phosphoric  acid  in  combination  with  alkalies, 
corresponding  to  5 per  cent,  of  soluble  phosphate  of  lime  in 
round  numbers.  It  is  altogether  a high-class  artificial  manure. 
Unfortunately  the  supply  of  good  bats’  guano  is  very  limited. 
Nitrogenous  Refuse  Manures. — During  the  past  twelve  months 
the  importation  of  high-class  Peruvian  guanos,  rich  in  ammonia, 
has  greatly  decreased  in  comparison  with  the  imports  of 
former  years.  The  price  of  high  ammoniacal  guano  has  lately 
risen  from  25  to  30  per  cent.  Sulphate  of  ammonia,  which  at 
present  is  worth  about  20/.  per  ton,  is  likely  to  advance  in  price 
in  spring.  Nitrate  of  soda  cannot  be  used  with  advantage  for 
certain  crops,  such  as  hops,  and  upon  soils  upon  which  more 
slowly  acting  nitrogenous  manures  appear  to  have  better  effect. 
It  may  therefore  be  of  interest  to  notice  the  percentage  of  nitrogen 
in  some  refuse  manures,  the  fertilising  value  of  which  mainly, 
if  not  entirely,  depends  upon  the  amount  of  ammonia  which 
they  are  capable  of  yielding  on  decomposition  in  the  soil. 
Besides  wool-refuse  or  shoddy,  several  samples  of  skin,  hair, 
feather,  and  leather-refuse,  flock-dust,  and  dried  blood,  have  been 
sent  for  analysis,  and  the  following  results  have  been  obtained: — 
Nitrogen  equal  to  Ammonia. 
Skin-waste 
5 
67  = 
6-88 
Leather-dust  (white) 
3 
GG  = 
4-58 
Leather  waste  (blue) 
01  = 
8-51 
Flock-dust  
G2  = 
9-25 
Feather  waste  
G 
31  = 
7-69 
Dried  blood 
10 
99  = 
13  = 33 
Both  the  samples  of  leather-waste  were  not  ordinary  tanned 
leather-waste,  but  leather  prepared  without  the  use  of  oak- 
bark,  or  a tanning  material  containing  tannic  and  gallic  acids. 
Ordinary  leather-wraste  has  but  little  or  no  value  as  a manure, 
for  the  combination  of  tannic  acid  with  skin,  which  constitutes 
common  shoe-leather,  resists  the  combined  decomposing  action 
of  moisture  and  air  in  the  soil,  in  a remarkable  degree.  1 have 
kept  leather  powder  even  dissolved  in  a solution  of  caustic 
