Artificial Manures for Swedes. 9 



5. Economical manure. 



6. Nut-refuse. 



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 paft 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 Ibs. of the surface soil through a inch sieve, 

 there were separated : 



Large stones, weighing 1 Ib. 6 ounces. 



Soil, passing through the sieve . . . 22 ,, 10 ,, 



24 Ibs. 



b. Of the soil passing through the inch sieve, 1 Ib. 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 T V in. diameter ; and the fourth with holes -g-V i n - diameter. 

 By this means it was divided into five different portions, the 

 relative proportion of which was as follows : 



No. 1. On 5 inch sieve were left 121 grains, fragments of limestones. 



2. ,, | 643 grains of soil, including a large 



proportion of limestones. 



3. A 2,246 grains. 



4. A i ft !' 192 



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-constituents 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. 



B 3 



