212 ON THE RELATIVE 



Art. LI.— on THE RELATIVE VALUE OF MANURES. 



By Mr. Karkeek. 



[At the annual meeting of the Probus Club, various tabular statements 

 were exhibited in the room, containing analyses of soils and manures, and 

 the results of experiments instituted with different manures by various 

 members of the club. The following paper, founded on these experiments, 

 was read by Mr. Karkeek.] 



He first suggested that wlien tlie produce of two unlike 

 manures iu the same experiment does not differ more than a 

 ton or so per acre, their effect should be considered as equal. 

 Among- the many experiments entrusted to his revising, 

 there were none that he could find so deserving of their 

 attention as those made -with bones and sulphuric acid. The 

 first experiment to which he would direct their attention, 

 with this new fertilizer, was made by J. H. Tremayne, Esq., 

 of Heligan. Three acres of strong loamy clay-slate soil 

 were appropriated for it. The seed was Skirving's variety, 

 sown in the latter part of May 1845, in drills of 27 inches 

 a})art. Each of the manures was mixed with 14 bushels of 

 wood and coal ashes per acre, which was drilled in with the 

 seed. The following statement shows the different manures 

 applied, the cost per acre, and the produce per acre : — 



No. Manure per acre. Cost. Produce. 



1. — 24 bushels bone-dust 12s. ■ ■ 30^ tons. 



2. — 8 bushels of bone-dust and 100 lb. of sulphuric 



acid 36 . . 28 



3. — 20 cart-loads of good farm-yard manure 60 . . 28 



The Swedes grown by the vitriolized bones were the 

 earliest in leaf, and fitted to hoe sooner than the other 

 plants. Ultimately there was no great difference in the 

 weight of bulbs ; but the difference in the expense per acre 

 was very considerable, the bone-dust and dung costing more 

 than the amount stated, as the extra expenses of carting and 

 sjireading the dung were not taken into the account. Mr. 

 Karkeek said, it should be observed that the crops in this 

 experiment, compared with those afterwards mentioned, 

 might appear large ; but it should be remembered that the 

 turnip crop of 1845 was one of the largest, and the one of 

 1846, perhaps, one of the smallest, since the general intro- 

 duction of artificial manures into the county. The propor- 



