Experiments upon Sioedes. 
79 
riot 5. Manured icith 0 cwfs. of Superpliosphate. 
tons. cwts. qra. lbs. 
rrodiico 21 2 3 12 
Iiicrca.so G 8 2 8 
The superphosphate used in these experiments had the fol- 
lowing composition :— 
Moisture 10-80 
*Organic matter 4'21 
Bi-pho.sphate of lime 20-28 
Equal to bone-carth rendered sohiWe (31-63) 
Insoluble phosphates 4-11 
Hydratcd sulphate of lime (oypsuiii) 4G-63 
Alkaline salts (common salt) 10-78 
Insoluble siliceous matter 3-19 
100-00 
* Containing nitrogen -34 
Equal to ammonia -41 
It will be observed that in this experiment 1 cwt. of this 
superphosphate gave nearly as much increase as 3 cwts. of the 
same manure. It would, however, be rash to generalise from this 
one instance ; nothing less than a dozen experiments in different 
parts of the field would have warranted the conclusion that on 
this soil 1 cwt, of superphosphate will give as good a crop of 
roots as 3 cwts. ; for the fact that the soil is not particularly rich 
in phosphoric acid renders such a supposition unlikely. More- 
over, we have a direct evidence in the Experiment No. 5 that 
the roots were grateful for an abundant supply of phosphates. 
6 cwts. of the same superphosphate here yielded the heaviest in- 
crease of all the 20 experimental plots. The superphosphate 
ued in this experiment was chiefly made from bone-ash, and 
contained but very little nitrogen. We have thus here another 
proof that a good crop pf roots can be obtained on clay land 
^ with superphosphate alone, containing but little nitrogenized or 
other organic matters. , 
Plot 6. Manured with 3 cwts. of Gypsum. 
tons. cwts. qrs, lbs. 
Produce 16 14 1 4 
Increase 2 0 0 0 
The gypsum employed in this experiment was ordinarily good, 
finely-powdered gypsum, which did not effervesce with an acid, 
thus proving that it did not contain any carbonate of lime. 
It seems that in this instance gypsum has had unusual effect on 
the produce. Probably the ashes with which the gypsum was 
mixed had a share in the increase. 
