14 Artificial Manures for Swedes. 



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 

 with 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 \vooden 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 6/. per ton. 



Plot V. Manured with 56 Ibs. of economical manure, or at the rate of 



4 cwts. per acre. 

 Cost of manure 5s., or 2/. 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 the unmanured plot 

 and the one dressed with 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 : 



Composition 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 . . r v r .- 683 



