152 
On the Comparative Value of 
the case of the four bullocks fed on decorticated cotton-cake 
and maize-meal than in the case of the four bullocks which had 
linseed cake as an additional food. 
Some of the bullocks did much better than others, as will be 
seen by the following particulars : — 
Bullocks. 
Increase in 
^Veigbt 
between 
ls(jvembei- 9, 
18iS, and 
January 17, 
lsT9. 
At a Cost in Purchased 
Food. 
Fed on Decor- C No. 1 . . 
ticatecl j „ 2 .. 
Cotton-cake j „ 3 .. 
and Maize-meal. (. ,, 4 .. 
lbs. 
1G2 
237 
117 
12i 
Per lb. 
5f'g 1 Showing an 
S/jj 1 Average 
GicZ. J per lb. 
Total Increase .. 
G40 
f Xo. 5 .. 
Fed on Liiisced-I „ 6 . . 
cake. j ., 7 .. 
I 8 .. 
ISG 
IG9 
115 
163 
5ld. l Showing an 
5j(Z. 1 Average 
Shi. i of Gid. 
tid. J per lb. 
Total Increase .. 
633 
VIII. — On the Compai-ative Value of Soluble and Insoluble 
Phosphates. By Dr. Augustus Voelckee, F.R.S. 
A GOOD deal of attention has lately been directed to a series of 
experiments which for some years past have been carried out in 
Aberdeenshire with a view of finding out the most suitable and 
economical manure for raising a crop of swedes. 
The results of these field-experiments apparently tend to show 
that mineral-phosphates in a finely ground condition are but 
little less efficacious than after treatment with sulphuric acid, 
and that it is more economical to manure root-crops with finely 
ground coprolites, and other kinds of mineral-phosphates, than 
with superphosphate made from these materials. If this prac- 
tical recommendation which Mr. Jaraieson has given to turnip- 
growers is based on experiments to which no objection can be 
taken, and if other experimenters in the main arrive at the 
same conclusions as Mr. Jamieson, it is clear that for the last 
twenty-five or thirty years agriculturists have been altogether 
wrong in applying superphosphate to their root-crops instead 
of the ground raw materials from which it is produced ; and 
