96 
Artificial Manures for Swedes. 
5. Economical manure. 
6. Nut-rct'use. 
7. Dissolved coprolites. 
8. Commercial dried night-soil. 
9. A mixture of sand, guano, dissolved coprolites, and superphosphate 
of bones. 
The field selected for the experimental trials with these ma- 
nures was almost perfectly level, and throughout of a uniform 
depth. It had been cropped alike in every part in previous 
years, and otherwise uniformly cultivated. The surface soil is 
shallow, and rests on the great oolite limestone, from which 
it is separated by a clayey subsoil of small dimensions. Alto- 
gether it is a turnip soil of but moderate quality, belonging to 
the class of calcareous soils, as will be seen by glancing at the 
subjoined analyses. 
1. Mechanical Examination of Soil of Experimental Field, 
Cirencester. 
a. On passing 24 lbs. of the surface soil through a ^ inch sieve, 
there were separated : 
Large stones, weighinE: 1 lb. 6 ounces. 
Soil, passing through the sieve . . . 22 ,, 10 ,, 
24 lbs. 
h. Of the soil passing through the ^ inch sieve, 1 lb. was 
riddled through a series of 4 perforated zinc cullenders, fitting 
into each other. The uppermost cullender was provided with 
apertures, measuring J of an inch in diameter ; the second with 
apertures ^ of an inch in diameter ; the third was perforated with 
holes tV in. diameter ; and the fourth with holes in. diameter. 
By this means it was divided into five different portions, the 
relative proportion of which was as follows : — 
No. 1. On J inch sieve were left 121 grains, fragments of limestones. 
2. ,, I „ „ 643 grains of soil, including a large 
proportion of limestones. 
3. „ t's „ „ 2,246 grains. 
5. Through the last sieve passed 2,882 
7,085 „ 
A mechanical examination of this description is useful, inas- 
much as it enables us to form some idea of the state of division 
in which the soil-c onstituents actually occur, and in experimental 
trials enables the reader to judge for himself whether or not the 
soil was sufficiently pulverised for the crop experimented upon. 
It will be observed by these data that the mechanical preparation 
of the experimental field has been carefully attended to. 
