194 
Value of Earth-Closet Manure. 
the three samples of earth-closet manures varied a good deal, the 
preceding analytical data do not admit of being readily compared 
with each other. I have, therefore, calculated what the compo- 
sition of the four samples would be when dried at the uniform 
temperature of 212° Fahrenheit. 
The following Table expresses their composition in a perfectly 
dry state : — 
CoMPOSiTiox of Earth and Three Samples of Earth-Closet Manure 
produced at West Eidikg Prison, Wakefield, in dry state (dried at 
212° Fahr.). 
No. 
1. 
No. 
2. 
No. 
3. 
No. 
1 
Earth for nse 
Earth 
once 
Earth 
twice 
Earth thrice 
Id 
used 
used 
used 
Closets. 
in Closets. 
In Closets. 
in Closets. 
* Organic matter and water ofl 
9 
88 
9- 
79 
11 
53 
12 
22 
Oxide of iron and alumina 
12 
95 
16- 
15 
14 
11 
12 
48 
Phosphoric acid 
18 
25 
•44 
51 
2 
21 
2- 
25 
2 
13 
2 
14 
1- 
44 1 
77 
90 
Alkalies and loss in analysis ../ 
1- 
35 J 
2- 
63 
1 
72 
74 
Insoluble siliceous matrur (clay 1 
71 
99 
68- 
93 
70 
30 
71 
01 
100 
00 
100 • 
00 
100 
00 
100 
00 
•31 
37 
42 
51 
•37 
45 
51 
•62 
A glance at the preceding analyses shows that the proportion 
of nitrogen in the soil increases but very little each time it is 
removed from the closet. 
Used once the soil gained only •06 per cent, of nitrogen, used 
twice it gained •ll per cent., and three times '20 per cent. If 
we divide by 3 the increase of nitrogen in the earth-manure 
passed three times through the closet, supposing the manure tc 
be perfectly dry, we obtain "066 as the average increase o 
nitrogen each time it is passed through the closet. It wil 
further be seen that after the soil had been used three time: 
over, the total increase of nitrogen amounted to only two-third 
of the small quantity originally present in the soil. 
The proportionate increase of phosphoric acid in the thre 
samples of earth-manure, as might have been expected, is rathe 
larger than that of nitrogen, but, after all, the soil in a perfect! 
dry state, after having been used three times, contained on! 
^ per cent, of phosphoric acid ; or a ton of such soil containe 
only 11 lbs. of phosphoric acid in round numbers, which 
equal to 25 lbs. of bone phosphate of lime. Half a cwt. 
