^EPT. 2, 1901.] THE TROPICAL AGRICULTURIST. 
1B3 
had the Aberdeenshire experiments been carried 
out more extensively in this country the actual 
value of finelj ground raw phosphates would have 
been demonstrated long ago. Basic slag being, how- 
ever, introdnoed just when these experiments in the 
north h^d terminatsd, atteutioa was naturally con- 
centrated upon it, especially as the cost was then so 
low, audit naturally became the fivoured material 
for field experiments, with iuoreasing success; 
though, as will be seen from Table I., its solubility 
was greitly inferior to that of basic super. 
Dr. DrEn: But the solubility of basic slag in a 
stronger solution, such as 1 per cent, wj,s mucli 
greater than that referred to in Table I. 
Mr. Hughes, coatinuiog, said no doubt a 1 in 100 
solution, would dissolve out more than his weaker 
solution, 1 to 1,000; but the relative solubility was 
still against b:.isio slag and in favour of basic super, 
as the following figures clearly indicated : — • 
Coin2)cirisoii of Soluh Hit-/. 
1 grm. of each of these materials was treated 
respectively with 2(10 c.c. of 1 per cent, solution of 
citric acid, 400 c.c. of 0'5 per ceot., 1,000 c.c. of 0 1 per 
cent., and 2,000 c.c. of 0 U.5 per cent.; allowed to 
stand 2i hours, with occasional stirring. 
Basic Bisic 
— Super, Slag. 
Portion soluble in 200 c.c. 1 per cent. . 94 70 64 70 
400 „ 0-5 , .. 9J-30 51'50 
,, „ 1,000 „ OT „ ... 9,5-70 38-30 
„ „ 2.010 „ 0 05 „ ... 30-30 
It would be seen that, while the solubility of the basic 
super remained practically constant up to a dilutioa 
of only one part of citric acid in 2,030 parts cold 
water, the solubility of the basic slag declined with 
the dilution enormously. He could not agi-ee with 
Dr, Dyer's suggestion that perhaps it would be more 
economiol to use ground phosphate instead of 
slaked lime. The lime was hydrated and in a very 
soluble form, whereas the raw ground phosphate 
would be coarse or tine according to the grinding, 
and the action of the acid in the superphosphate 
would be directed rather upon the carbonate of lime 
than upon the phosphate of lime. In conclusion he 
would say that the new manure must stand upon 
its own merits; and it only remained for him to 
thank those gentlemsn who had supported him in 
exoressing their opinion that the manure would 
prove useful. Experience had shown thiit basic slag 
was a very valuable manure, and if his manure was still 
more soluble and rapi ily available, as was indicated by 
its much greater solubility in the particularly weak 
solution of citric acid {I in 1,000), he had every reason 
to hope that the field experiments would prove it to be 
a quitk-acting and reliable manure, which was just 
what the farmer wanted. — Journal of the Society of 
Chemical Iiidustri/. 
CULTIVATION OF SEEDS FOR OIL AND 
CAKE EXTRACTION. 
SUNFLOWER AND CASTOR OIL PLANT. 
Sib, — Seeing that there are some planters thinking 
of going ia lor the cultivation of snnflovver seed 
Cfor oil extractionj, I thought it might not be out 
of place to give a few particulars with reference to 
the growing and treatment of the seed to be con- 
verted into oil. 
I think a valuable vegetable oil industry might 
be carried on in Oeylon if the planters would go in 
for the cultivation of the various kinds of oil plants, 
such as castor oil, sunflower seed, pea nuts, mustardj 
cotton seed, gingelly, and even olives, I think, might 
be grown to advantage. 
I have extracted a very large quantity of oil from 
the above variety of seeds, grown in Victoria by the 
Department of Agriculture, in whose services I was 
for several years as manager of the department's 
To encourage the oil Fced industry the depart- 
ment gave a bonu5 of £2 per acre to farmers to 
cultivate the seed for three years, and extracted 
the oil for them at a nominal cost, refining and 
packing the oil ready for the market. 
If the Caylon Government would do likewisp, the 
planters would only be too glad to try some new 
industry to help them over the present very hard time. 
Sunflower seed : 8 lbs. of seed per acre is enough 
to plant, the oil cake is excellent as a food for 
horses, cattle, pigs, t&o., and is worth about £6 per 
ton 'for feeding purposes. 
The best to grow for oil is the small black variety 
(granditiora) as it yields the larger precentage of oil, 
20 to 25 per cent of good oil, almost equal to the be.st 
olive oil ; it is a first class table oil and there ia 
always a gjod market for it if properly refined. 
When in Colombo I could let you see samples of the 
above oils if you care to inspect them. 1 hope to 
be down in a week or so. 
Since v?riting the above, I see another correspond- 
ent asks information about the castor oil plant, 
There are two kinds of this seed that I have manufac- 
tured into oil, the large and small variety- The 
small is the best, as it contains from 40 to 42 per 
cent, oil ; the price of the seed varies from K5 to R6 
per cwt. It can be obtained in Bombay, and is 
grown in the Gujarat district ; castor cake is worth 
from RIO to R50 per ton, and it is an excellent manure, 
as it contains a lai-ge percentage of nitrogen. Ic 
should find a ready market in Ceylon. 
For " Palma Christi's " information ; — 
(1) In my opinion it is better to put in seed 
say 3' M 8'— two seeds in a hole about 2. 
(2) Bombay, that which is grown in Gujarat dis- 
trict is the best. 
(3) After the seed is ripe enough, it is cut off in 
clusters, allowed to dry an! then trampled on by 
bullocks, same as paddy, then collected and cleanetl. 
(4' About 40 bushels per acre, or more on good soil. 
(5) There is a good market both in England and 
France for good castor seed, also oil ; seed is worth 
sav in Colombo from R5 to RS per cwt. Oistor 
cake should bring at least RiO to RoO per ton. 
(6) By hydraulic pressure, a small plant could 
be got for £500 or 600, but this would depend on 
what power could be got on owner's property. 
(7) in my opinion plants grown as an annual 
give best value. After seed is sown, there is little 
or no attention required until seed is reidy for 
plucking. 
(8) The plants would certainly crop best grown alone. 
AVhen in Colombo I could give you more infor- 
mation than by writing, such as cost of machinery, 
refining oil, &c. — Yours, ifcc, 
E. WILSON. 
Engineer, Finlay Muir & Co. 
Katugastota Estate, Katugastota, August 10th.— 
" Local Times." 
Weeds. — On new and unexhausted lands the bad 
effects of weed growth ai-e doubtless due fully as 
much to the waste of moisture going on through 
their leaves as to the competition with the crop for 
plant-food. Hence all good orchardists are very 
careful ab ut keeping their ground clear in summer: 
but it must not be forgotten that by doing so they 
quickly deplete their lands of vegetable matter 
which requires systematic replacement by. green 
manuring if production is to continue normal'^, yet 
of the two evils, the loss of moisture is more 'o be 
dreaded, and very generally in practice the more 
difficult to remedy. — Professor Hilgakd. Weeds in a 
a dry country waste enormous quantities of soil mois- 
ture, each pound of weeds reducing the growth of 
corn by two pounds. Clean farming conserves mois- 
ture for the useful plants and useful plants produce 
more bulk as well as more value from a given amount 
if available moisture. — W. M. Hays, Minnesota. 
Agricultural Experiment Statioa, — AjirievltKral Qa^ett^ 
vf jS: S. Wales, 
