86 
THE TROPICAL 
AGRICULTURIST. 
[July r, i8£i. 
No. 1 
No. 2 
80 487 
74-674 
Water 14'442 
19-177 
(5-071) 
(6-149) 
1 -805 
1-664 
•209 
•193 
•569 
•497 
•430 
•717 
067 
•171 
•951 
1-068 
•575 
•827 
•159 
■217 
•239 
•862 
100-000 
100-000 
•446 
•644 
■250 
•092 
COPPER MANURES : MORE ABOUT POTASH. 
Colombo, 12th May 1881. 
Sir, — It may help towards a more intelligent use 
of artificial manures, if we examine the composition 
of Ceylon made cattle manure. Two samples received 
from Mr. Joseph Fraser of Damboolagalla estate, 
Matale, had the following composition. No. 1 is the 
analysis of cattle manure from cattle fed upon coco- 
nut poonac and guinea grass, the bedding being 
mana grass. No. 2 is the analysis of manure from 
cattle fed upon guinea grass only, the bedding mana 
grass. 
Moisture expelled at 212° F. 
Ash 
Insoluble Silica 
Soluble Silica 
Oxide of Iron, Alumina and ) 
Phosphates i 
Lime 
Magnesia 
Potash 
Chloride of Sodium and Soda 
Sulphuric Acid 
Carbonic Acid and loss 
Nitrogen 
Phosphoric Acid 
The most striking feature, in these analyses, is the 
fact, that of the four chief manurial ingredients viz. 
nitrogen, phosphoric acid, lime, and potash, by far 
the most abundant is potash which averages fully 18 
per cent of the manure ash. The proportion of potash 
is much higher than in English farm yard manures, is 
indeed double as great. Analyses of the ashes of mana 
grass, guinea grass and coconut poonac, separately, would 
be desirable to ascertain the proportion of potash and 
other ingredients derived from each of these sources. 
The percentage of potash in the manure from cattle 
fed on guinea grass only is slightly higher than in 
the other, when calculated into the weight of the 
manure as it stands ; but if calculated into the weight 
of the ash of the manure, it is slightly higher in 
that from cattle fed upon both poonac and 
guinea grass. The latter manure has a very decided 
advantage in respect of phosphoric acid. It was con- 
trary to my expectation to find No. 2 richer in 
nitrogen than No. 1, and in the case of a substance 
so difficult to sample, from its want of homogeneity, 
as citfcle manure: more analyses are desirable before 
accepting this as a general fact. It was, however, to 
some extent confirmed by analyses of dung from cattle 
fed on guinea grass only (analysis No. 3), and tliat 
from cattle fed on coconut poonac as well (analysis No. 4). 
No. 3. No. 4. 
Moisture expelled at 212° F 73'500 75-186 
Organic Matter and combined Water 20^53 21195 
Ash (6-247) (3-619) 
Insoluble Silica 3 667 2-221 
Soluble Silica -328 159 
Oxide of Iron, Alumina and phosphates -499 -438 
Lime 
Magnesia 
Potash 
Chloride of Sodium and Soda 
Sulphuric Acid 
( aroooic Acid and loss 
Nitrogen 
Phosphoric Acid 
Here again we notice that 
1 037 
•078 086 
•213 -091 
•076 043 
•112 -078 
•237 -039 
100-000 100000 
•529 -392 
•139 ... -174 
the dung from cattle 
fed upon both coconut poonac, and guinea grass, al- 
though the percentage of ash is much lower, yet the 
phosphoric acid is higher than in the guinea-grass-fed 
cattle dung. When guinea grass is the only feeding 
material, it would appear that both the dung and total 
manure are much richer in lime, than when coconut 
poonac is used as well. 
From the large percentage of potash in Ceylon-made 
cattle manure, those holding different views regarding 
this substance will, most likely, drawn opposite con- 
clusions as regards its place in artificial manures. Thus 
the nitrogen and phosphate manurists will argue, 
that the very fact of cattle manure being richest 
in potash shows that the soil from which it 
was derived is best able to supply this ingredient, 
and there is therefore no occaeion to add it 
to our artificial manures. The nitrogen, potash and 
phosphate manurists, on the other hand, will argue, 
that, since potash is such a conspicuous ingredient 
of cattle manure (the stand-by of the planter), it is 
wise to introduce a considerable proportion of it in 
manures for coffee, of which it forms by far the most 
abundant mineral constituent. The balance of what 
little experimental data is as yet before us decidedly 
favours the latter view. We have the testimony of 
Mr. Graham Anderson and Mr. Tilputt, founded on 
actual experiments, in its favour, the said experiments, 
moreover, having been carried out on soils richer in 
potash than those of Ceylon. In the March number 
of the Journal of the Chemical Society an extract 
from a leading continental scientific magazine informs 
us, that "experiments which were carried out at 
Potsdam shewed the most suitable manure for fruit 
trees to be a mixture of potash sulphate and super- 
phosphate which increased the number of blossoms 
considerably." Mr. Fraser also, I understand, has 
found that on Damboolagalla estate those fields at 
least, the analysis of which shewed a lower per- 
centage of potash responded very well to som- 
breorum, which is essentially a mixture of po- 
ash sulphate and superphosphate of lime. 
Of the commercial salts of potash, besides wood 
ashes, our choice from considerations of expense, is 
probably restricted to the nitrate, muriate, and sul- 
phate. The first can be obtained from India. A very 
good sample for agricultural purposes submitted to 
me by a Colombo firm contained nearly 90 per 
cent salts of potassium, the nitrate constituting nearly 
80 per cent. Much of the crude Indian nitre, how- 
ever, is greatly inferior to this, containing much 
common salt; but, if cheap enough, is useful as a 
manure. Nirre of 80 per cent furnishes fully 11 per 
cent of nitrogen, so that is a highly nitrogenous as 
well as potassic manure. 
Commercial muriate of potassium contains about 
88 per cent of muriate and costs about £8 or less 
per ton. A crude muriate of potassium and magne- 
sium called carnallite can be had from Stassfurt in 
Prussia for less than a third of the cost of the 
purer salt; but, as it only contains 25 per cent of muriate 
of potassium, the purer salt would be the cheaper as a 
source of potassium. Kainit is a crude postash sulph- 
ate which comes from the same mines at Stassfurt. 
Voelcker's analysis of it is as follows : 
Moisture 3 '36 
Water of combination .. .. 10 '88 
Potassium Sulphate 2443 
Calcium Sulphate 2 72 
Magnesium Sulphate 13"22 
Magnesium Chloride 14'33 
Sodium Chloride 30 35 
Insoluble Silicious Matter "71 
100 00 
A cheaper source of sulphate of potash, if still to 
3 had at its former price of about £8 per ton, it 
