On Bats' Guano. 
63 
Bats' Dung from Arkansas. 
Some time ago I received two samples of bats' dung taken 
from caves in Arkansas. One of them was dry and earthy in 
appearance, and marked " Old deposit ;" the second, labelled 
" Fresh deposit," was very damp, lumpy, and dark coloured. 
On analysis the two samples yielded the following results : — 
Composition of Arkansas Bats' Guano. 
*Moistiire 
Organic matter and salts of ammonia 
tPhosplioric acid, solnble in water .. .. ) 
t „ , insoluble in water .. .. j 
Lime 
§Ni trie acid 
Alkaline salts, oxide of iron, alumina, and"! 
otlier substances not determined .. ../ 
Insoluble siliceous matter 
* Containing nitrogen 
Equal to ammonia 
t Equal to tribasic phosphate of limcl 
rendered soluble by acid / 
X E pal to tribasic phosphate of lime 
§ Containing nitrogen 
Equal to ammonia 
No. 1. 
Old 
Deposit. 
No. 2. 
Fresh 
Deposit. 
6-74 
21-32 
6-64 
6-11 
1-80 
33-53 
44-63 
/ 1^92 
\ 1-84 
1-87 
8-40 
15-09 
3-12 
42-30 
4-69 
100-00 
100-00 
2- 48 
3- 01 
6-62 
S-04 
4-19 
14-49 
•46 
•56 
4-02 
2-18 
2-65 
Notwithstanding the wet condition of the fresh deposit, it 
yielded 8-04 per cent, of ammonia and 8'4 per cent, of nitric 
acid, corresponding to 13^22 per cent, of nitrate of soda, and 
containing 2-18 per cent, of nitrogen, equal to 2-65 per cent, of 
ammonia. Thus, altogether, the fresh bats'-dung contained 
8-80 per cent, of nitrogen in the shape of nitrogenous organic 
matters, ammonia-salts, and nitrates, corresponding to 10-G9 per 
cent, of ammonia. The fresh deposit was full of fragments of 
the wings of insects, presenting a beautiful appearance under 
the microscope. It had no offensive or pungent smell, and did 
not contain any appreciable quantity of volatile carbonate of 
ammonia. About one-half of the phosphoric acid found in the 
analysis was soluble, the second half was insoluble in water, 
and both together represented 8 per cent, of tribasic phosphate 
of lime in round numbers. The presence of a considerable 
