214 ON THE RELATIVE 



11 tons per acre. The Rev. T. Phillpotts, of Feock, insti- 

 tuted some very extensive experiments witli ditierent manures 

 for turnips, and the result confirms the experiments pre- 

 viously mentioned, as he obtained as heavy a crop with 4 

 cwt. of super})hosphate and ^ cwt. of Potter's artificial 

 g'uano mixed, at an expense of 4:6s. per acre, as with 32 

 bushels of bone-dust, at a cost of 96^., or with 32 bushels of 

 bone-dust and |- cwt, of Potter's gaiano, at a cost of 102s., or 

 with 28 loads of rich butchers' dung-, at a cost of IGSs. per 

 acre. The next experiment was instituted at Trewithen, by 

 Mr. Trethewy, with four different kinds of manures for 

 turnips, on an old ley pasture of a loamy character, resting- 

 on arenaceous slate, valued at 30^. per acre : — 



No. Manure per acre. Cost. Produce. 



1. — Ichaboe guano 36*. . . 23^ tons. 



2. — Liebig's patent manure 35 . . 24 



3. — Dry superphosphate 45 . . 232 



4.— Bone-dust 72 . . 20^ 



The most interesting* part of this experiment is the effect 

 of " Liebig''s turnip manure," which produced the larg-est 

 crop at the smallest expense. This manure pushed the 

 turnip plant more rapidly forward than either of the others ; 

 but it will be seen that the same effect does not always 

 attend its operations ; for, in the very next experiment, made by 

 the same party on Carnvvinick estate, and in a different kind 

 of soil, it had quite a contrary effect. This was on a plot of 

 ground of six acres, purposely reclaimed from the wastes 

 adjoining- Trelyon common, by stubbing-, beating-, and burn- 

 ing-, as is usually practised in cultivating- the g-orse wastes in 

 this comity. The soil is of a coarse character, resting- on 

 arg-illaceous slate : — ■ 



No. Manure per acre. Cost. Produce. 



1. — Liebig's turnip manure 35*. . . 12;J- tons. 



2.— Saldanha Bay guano, No. 1 26 . . 27 



3. — Superphosphate of lime 45 . . 20j 



4.— Bone-dust 72 . . 26f 



5. — Ichaboe guano , 38 . . 20^ 



6. — Saldanha Bay guano, No. 2 38 .. 26^ 



In remarking- upon this experiment, Mr. Karkeek said, the 

 first thing that attracts the attention is the small produce 

 from Liebig's manure, compared with its eflect in the former 

 exj)eriment ; for, in this case, it appeared to have acted the 

 Avorst of the lot. He then proceeded to account for the 



