106 Experiments at Burcott Lodge Farm, Leighton Buzzard. 
Every one who has given even the most careful attention to 
the carrying out of experiments knows that they are subject to 
a vast variety of circumstances which may affect them. The 
soil may in the first instance be rich or poor, light or heavy, 
rough or fine. The season, the climate, the time of applying 
the manures, the method, &c., all these and many more con- 
tingencies may occur. 
Thus, by an accident, a few heaps of dung had during last 
winter been carted across the land where the experimental 
artificial-manure plots were placed, and although it was both 
small in weight and poor in quality, the little nitrogen in the 
dung told most plainly for about 3 yards wide over the crop of 
swedes, which were nearly doubled in size where the sprinkling 
of dung was laid. 
The preceding experiments were carried out at Dr. Voelcker's 
request, and the following analyses show the composition of the 
ground and of the dissolved coprolites used in the experiments : — 
Composition of a Sample of Mineral SuperpTiospTiate used in 
Mr. B. Vallentines Experiments. 
Moisture 11-75 
Orgauic matter and water of combinatioa .. 10 "35 
Monobasic phosphate of lime 17*48 
Equal to tribasic phosphate of lime (bone) ^r)^ .^^n 
phosphate) rendered soluble by acid .. •• ) 
Insoluble phosphates 4 "49 
Sulphate of lime I 46 • 79 
AUialine salts and magnesia J 
Insoluble siliceous matter 9 • 14 
100-00 
Composition of a Sample of finely ground Coprolites used in 
Mr. B. Vallentine's Experiments. 
Loss on heating 4-42 
*Phosphoric acid 26-18 
Lime 44-54 
Oxide of iron, alumina, carbonic acid, &c. 16-81 
Insoluble siliceous matter 8-05 
100-00 
♦Equal to tribasic phosphate of lime .. .. 57 '15 
