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X. — Experiments on the Use of Phosphates in growing Swedes 
at Tubney Warren in 1869.* By J. W. Kimber, m'.H.A.C. 
The agricultural value of phosphates of various kinds and of 
different degrees of solubility being a somewhat undecided 
question, it was thought desirable to ascertain by experiment 
tlie merits of some of these as manure, at least on light sandy 
soils on which phosphates in some form generally constitute 
the staple manure for root-crops, and thus the chief means of 
enriching these poor lands. 
At my request Messrs. F. C. Hills and Co., of the Chemical 
and Artificial Manure Works, Deptford, kindly supplied me 
with a variety of phosphatic substances from which the following 
were selected for trial : — 
1. Bone-dust, containing from 45 to 50 per cent, of phosphate. 
From boiled bones. 
2. Dissolved coprolite or mineral superphosphate, containing 
27 per cent, of phosphate made soluble. 
3. Coprolite powder (grey), containing 59 per cent, of phos- 
phate. 
4. Rhenish phosphorite powder, containing 65 per cent, of 
phosphate. 
5. Dissolved bones prepared from bone-ash and bones, chiefly 
the former, containing about 40 per cent, of phosphate, of which 
30 to 32 per cent, were made soluble. 
G. Precipitated phosphate obtained from Rhenish phosphorite 
dissolved in muriatic acid and precipitated with lime. 
This contained 29 '46 of precipitated insoluble phosphate 
(besides 0*70 soluble). The result of the analysis of this sub- 
stance was not received until after the manures were applied. 
It was then found to be poorer in phosphate than anticipated, 
and the quantity applied should have been after the rate of 
6 cwt. per acre instead of 5 cwt. 
The plan of experiment proposed was to apply these six 
substances to the growth of swedes the first year, and to observe 
their effects on this crop and on the succeeding crop of barley 
in 1870, and on the seeds following in 1871. For this purpose 
a piece of land was selected which had grown a crop of wheat 
in 1868 after clover, the wheat having a fair dressing of farm- 
yard dung. 
It was determined to apply the various manures in quantities 
of about equal money value, taking as a standard 5 cwt. of the 
* These experiments were intended to be the commencement of a series, which 
has not been carried out, owing to a variety of causes ; but Ihe results now given 
appear worthy of record in comparison with those obtained last year at Woburn. 
— Ed. 
