Artificial Manures for Swedes. 
101 
evident that in all probability superphosphate of lime would 
surpass the other manures in its effects upon Swedes. Experi- 
ence has proved it to have been the case. 
In the preparation of the superphosphate the fine bone-dust, 
of which an analysis has been given already, was first moistened 
witli one-third its weight of boiling water, and after the water 
had been thoroughly soaked in by the dust, one-third of its 
weight of brown oil of vitriol was added. The mixture was 
made in a wooden trough, from which it was removed and 
placed in a heap, after it had become sufficiently consolidated. 
It was made a considerable time before the sowing of the turnips, 
and had thus time to become thoroughly disintegrated in the 
heap and dry on keeping. Before its application to the land, 
it was broken down with a wooden mallet into a fine powder. 
Boiling water was found to assist the dissolving action of the 
oil of vitriol in a very high degree : it can therefore be recom- 
mended as greatly preferable to cold water. The cost of the 
dry home-made superphosphate was 6Z. per ton. 
Plot V. Manured with 56 lbs. of economical manure, or at the rate of 
4 cwts. per acre. 
Cost of manure 5a\, or 21. per acre. 
In a very short time after the bulbs had begun to swell, this 
plot was left behind by all the other experimental plots, the 
undressed portion excepted. The difference in the appearances 
between this plot and the other manured plots became more and 
more striking as the crops approached maturity, when the most 
unexperienced eye could observe that the economical manure 
had done little good to the swedes. It was, indeed, impossible 
to observe the slightest difference between tlie unmanured plot 
and the one dressed Avith economical manure. This unfavour- 
able result cannot surprise any one who knows that phosphoric 
acid applied in a form in which it can be readily assimilated by 
the growing plant, more than other fertilizing constituent, benefits 
root crops, if he throws a glance at the following analysis : — 
Composit 'mi of Economical Manure. 
Water 36.525 
Protosulphate of iron (green vitriol) 23*756 
Sulphate of lime '860 
Sulphate of magnesia '204 
Bisulphate of potash 4.677 
Bisulphate of soda 10-928 
Sulphate of soda (Glauber salt) 15* 143 
Sulphate of ammonia 2*648 
Insoluble siliceous matter (sand) 5*850 
100*591 
Containing ammonia -683 
