October i, 1891.] THP TROPICAL AQRICULf URIST. 
24s 
With other produce the same course should be pursued. 
In this way it would be seen what demand the plant 
makes on the soil for available food at different periods 
of the year. 
Having clecided that a manure is required and what 
it is to be, the queftiou is how to supply the estate 
with it at ' he least cost in the most suitable form. All 
manures vary greitly in quality; a merchant guarantees 
the bones or other manure supplied as pure, but the 
quality of pure bones and other manures of undoubted 
purity are of very different mannrial value. The follow- 
ing analyses show how widely pure bones vary in 
quality: — 
Analyst. Maoadana. ibson. 
Highest. Lowest. Hignest. Lowest, 
per cent per cent per cent per cent 
Phosphates 57-08 44 72 48-14 4495 
Ammonia 
5-23 
Alkaline Salts -85 
3-34 
•32 
1-91 
•63 
Analyst. 
Phosphates 
Ammonia 4 48 
Alkaline Salts — 
Huehes. 
Highest Lowest, 
per cent per cent 
54-03 39 40 
3-01 
Pringle. 
Highest. Lowest, 
per cfnt per cent 
52-25 43 -77 
5^09 3-25 
2-02 -50 
Sibpon unfortunately does not give the ammonia, 
and Hughes unfortanitely does Rive the carbonic acicl 
with the alkaline salts which prevents comparison, but 
on page 107 of his report on " Oeylou coffee soils and 
manures " the composition of Indian bone dust is 
assumed to ba 
per cent. 
Nitrogen 3 5 Equal to Ammonia 4 25 
Plio-poric aeid 24 „ j, Phosphates 52-32 
Potash 1 
Here then in puro bones or what is sold as such 
we have Phosphates (t. e, Tricalcic phosphate) 
varying from 39 40 per cent up to 57-03 per cent and 
the Ammonia from 3 01 percent up to 5'23 per cent. 
The alkaline salts found in bones are generally 
assumed to be magnesia and soda, but in some samples 
a notable quantity of potash is found, whether it is 
derived from the food of the animal or from accid- 
ental mixture with ashes I am not able to say. The 
Agricultural Societies of Britain generally fix selling 
price units for the season and manure? are valued on 
them; for Southern India and Ceylon the units might 
be fixed by the Planting Assooiatioas and the Chambers 
of Commerce. 
For the present I will lake bones and oil cake as 
the standards for phosphat's and nitrogen. It is 
necessary in the first place to decide what constitutes a 
fair marketable quality of bones and Hindy oilcake. 
Ill England the manura manufacturers generally buy 
bones on a basis of 48 per cent phosphates ({.e. Tri- 
oalcic phosphate) and 4 per cent ammonia. Numer- 
ous analyses show this to be a fair average. 
For valuinsr bones the alkaline salts are not oon- 
eidered, only the phosphates and ammonia being paid 
for. Assuming the price per ton for bone flour of 
that quality to be EGO in Bangalore, Colombo and the 
west ooaet, we can estimate the value of other 
manures in compariFon with it. Castor hindy may 
eafcly be assumeil to contain 6 per cent of ammonia 
and costs say R36 per ton ; the ash though very 
valuable ns plant food is not valued, as it generally 
corresponds to the per cent of ammonia. We thus 
get the value of sis ton units of nmmonia in oil cake 
at Thirty-six rupees or rupees six per unit per ton ; 
that in raw bono flour is worth as much per unit. 
D.duoting the value of four units of ammonia R24 
from tho total price of the flour we get R36 as the 
value of 18 units of phosphates or three-f'-urths of a 
rupee pir unit per ton for phosphates. The Home 
price is about one shilling and uinepence for phos- 
phates and eleven to twelve shillings for ammonia. 
So that these manures here are cheapi'r than in Eng- 
land. As showing the valuable nature of castor 
cake and of its Bsb the following analyses may be of 
interest : — 
Castor cake 
parts per 100. 
Moisture ... 
Oil 
Albuminous Compound 
Mucilage gum &o. 
Woody Fibre... 
Soluble Ash,. 
Insolnble matter, sand, &o. 
Containing Nitrogen ... 
Equal to ammonia ... 
Soluble Ash Analyses 
Lime 
Magnesia ... 
Potash 
Soda 
Pbosphorio Acid 
Sulpi'urio Acid 
Chlorine... 
671 
. 1003 
. 30-29 
. 19-64 
. 27-34 
. 5-16 
. -83 
10000 
. 5^05 
. 6-13 
. -09 
. -67 
. 1-98 
. -76 
. 1-21 
. -24 
. -21 
5-16 
Anplyaes of the ash of oil cakes are seldom made, 
but the proportion of phosphoric acid worked ont to 
phosphates is equal to 2-64 per cent, worth very nearly 
R2 per ton, and there is potash 1-98, worth about 
another two rupees. But the 116 paid for each unit 
of ammonia covers that. 
The following are the generally accepted propor- 
tionate values of phosphates and ammonia. 
Phosphates, Ammonia. 
90 per cent pass through screen 
Bones ^ inch mesh 20 132 
Meal 1/6 „ „ 21 138 
Flour 1/80 „ „ 22 144 
Fish whole (about the size of sprats) 21 144 
Meal 1 16 22 150 
Oil cake 1/16 — 144 
In England the price of ammonia chiefly depends 
on the supply of ammonia sulphate, in India most 
probably on oil cake ; a determination of the nitro- 
gen in it, expressed as ammonia is all that ia 
required to determine its valne, as the consumer 
knows that from a mennrial point of view, if the 
cake is rich in nitrogen the percentage of, to him, 
valuable ash will be high, and tbe valuless oil low, 
and vice versa. 
Carriage is a most important item to most planters, 
and an oil cake which has over six per cent of am- 
monia is more valuable proportionately to them 
on this account than one with less, though both 
are paid for at the same rate per unit ton. The 
buying of oil cake by analyses is the fairest plan both 
for planters and laanufaoturers. For instance sup- 
pose two coast firms offer oil cake one at K36 with 
6 per cent Ammonia and one at B42 per ton with 
7 per cent delivered on the coast. The upoountry 
planter has we will say RIO per ton to pay for 
carriage, therefore the prices of the cakes on his 
estate are respectiyly R46'for6 percent, or R7 and 
66 cents or K7, 10 annas and 8 pice, while the 7 per 
cent costs K52 per ton or R7 and 43 cents or R7 6 annas 
10 pice. Let us suppose the order to be lor 100 tons 
6 per cent or the equivalent in 7 per cent, then tbe 
bill stands as follows: — 
100 tons 6 per cent at E36 . . . . E3,600 
Carriiige at RIO ., 1,000 
Cost on the estate 
.. R4,600 
Ammonia supplied 6 tons cost per ton . . R766 
Only 85 tons 14 cwt. 1 qr. of 7 per cent are 
required to supply 6 tons Ammonia therefore the cost 
is roughly 85 tons 14 cwt. 1 qr. at R42 , . B3,600 
Carriage on the above at RIO . , 857 
R4,457 
G tons Ammonia supplied cast per ton 
B743 
