October i, 1891.] THE TROP10A1- AQWOULTURlSr. 
24t 
THE, ARTIFICAL PROPAGATION OF PEARL 
BEARING SHELLS AND THE PROD V 
TION OP PEARLS BY ARTIFICIAL 
MEANS. 
All the fcilorts as yet made in Ceylon and 
Southera India to propagate ariifioially the pearl 
oysters have been failures, chiefly, we believe, 
because the experiments were carried on in waters 
too shallow for the healthy life of the bivalves. We 
feel muoh Qonli<ience that sucoess will yet be attained, 
and wo certainly shall not despair until a fair trial is 
given to coir cables, or strong, coarse, wide meahtd 
coir nets anchored over the pearl bank region, so 
ns to float a couple of fathoms or so below the 
surface of tlio sea, We are not aware that any 
experimonla have been tried in the dirootion of 
inducing our " oyi-ters " to produce artificial 
pearls by irritation of the animal, or by the 
introduction of foreign bodies to become the 
nuclei of layers of nacre, In Australia a 
large msasura of euoeess seems to have attended 
experiments for the propagation of shells 
(mainly v/e suppose the great mothero'-pearl 
jielJers) and tbu artificial production of pearls. 
Oui- la'est news on the tubject is contained in 
ilie following telegram in the Aryus : — 
" Thurscl*y Islaii.l, Aug. 24. — Exptrimenis iuili.ted 
by tho oonimisjioner of fi-.heriea, Mr. Savdle 
IC ut, t va 5 ens ago in the liif etiou of causiog mother 
of p - il 6h'; Is 10 proilucG psiirls by avtifioial trent- 
mta [A-uve'' ; u istatitially succeEsful and enoouragcs 
tliO eX[.LC :itii.u -J' impGitint d^velopmti.ts io coijuec- 
tioa v/it'u the cultivation of p ari shell, which are now 
proved pet led ly feasibls. Tbe shells in the fxpori- 
men a\ nursery at Vuren Point are progiessiug well and 
propagating " 
Unpt. Donuan will, of course, "take a note on." 
In the South iSea Islands, corals have been sucoess- 
iully propagated by cuttings ! 
SOIL ANALYSES AND THE VALUE AND 
VALUATIONS OF MANURES. 
Althouiih the elaborate letter by Mr. Pringle 
Vihich wd publish below was written primarily with 
refeience to ooft'eo in South Coorg, the general 
priociples propounded apply as much to tea soil 
and tea as to ocfl'ea soils and coffee. In the olden 
da)s when coffee WiS King of Ceylon products, and 
btfore leaf diseare appeared to produce "insidious 
dtfunotion," many of us, in our attention to crop, 
were apt to forget the value of leaves to both bush 
and crop and also the demands they made on tree 
and soil. Hemileia vastatri.v taught us a striking 
lesson in vegetable physiology, by the process of 
weakening and finally killing the cclioe bushes 
from exhaustion, in their desperate efforts to 
produce crops of leaves, which scarcely appeared 
when their life juices were absorbed by the 
paraate. It is the prevalent theory, and it is true, 
that our climate specially favours the pro- 
duction of leaf : the rapidly increasing tea crops 
conclusively prove that this is the case. But it 
does not follow that exhaustion and even death 
mny not ultimately be the result of the prooesses 
of constaat leaf-plucking and branch and twig 
pruning, unless the elements thus abstracted are 
rejtored to the soil and that in the best possible 
foim. If moderate manuring could be afforded, 
it would be useful in the early years of an estate ; 
but as the plantation advances in age, the recu- 
perative and yielding powers of the bushes must 
on every principle of agricultural chemistry, 
diminish, unless the detioienoies of fertihzing 
31 
substances in the soil are supplied. Analyses 
of the soils will then bo useful as revealing the 
element or elements chitfly needed ; but, happily, 
even if this information cannot be obtained, a 
planter cannot go wrong in applying cattle shed 
manure and all "dirt in tin wrong place " to his 
fields, if none, or only a limited quintity of 
natural manure is available, then an artificial ap- 
plication in the ehape of good bones and 0 
castor cake is as valuable for tea as it ever was 
for coffee. Fish and other specially ammoniacal 
substances are also valuable, but our chief de- 
pendence must be on bones and " poonae, " 
what Mr. Pringle calls " hindy." The quality of 
each, however, varies considerably, and although 
the good faith of the leading dealers in the two 
articles named can be, as a rule depended on, 
yet it is well that analyses should be resorted 
to, especially where large quantities may be ordered. 
It will be seen that Mr. Pringle deems an applica- 
tion of iron sulphate advantageoua to soma 
soils. In most of our Ceylon soils, there is, 
naturally, a proportion of iron which (and we may 
say the same of clay) render them far better 
calculated for the growth of tea than for coffee. 
Our climate is, on the whole, one of the beat 
tea climates in thg woill. itather too much 
wet is, doubtless in some districts, an obstacle to 
the withering process in the case of gathered 
flush, but science founded on experience is rapidly 
providing remedies. 
The facts and figures adduced and the principles 
enforced by Mr. Pringle cannot fail, wa submit, to be 
of value to the tea planters of Ceylon, when deciding 
on the manures to apply and the mode of applying 
them. We fear that on but lew of our estates 
could tbe •' broadcast " process be carried out, 
although it is doubtless the best in theory. But 
that is a matter of detai'. The great lesson to 
be learned and praotically applied is, that the 
luxuriance of the growth of the tea plant in 
Oeylon and the unexpectedly large and increasing 
yield of leaf per acre are the strongest possible 
arguments against evading the duty of restoring, 
us far as we can, to the soil whence our crops 
come, the elem3nts of which we are constantly 
depriving it. 
« 
THE VALUE AND VALUATION OF 
MANURES: PABT I, 
By William Prinolk, m. s. c. i., 
late agbicdltural chbsiist to messrs. matheson & co. 
IN OOOBO. 
( Under special arrangement for publication in the 
" Ceylon Observer'" and " Tropical Agriculturist.") 
Every planter and agriculturist sccepts the dictum 
that minures are valuable aids to the cultivation of 
crops; sometimes tlieir value i.s questioned, but this 
generally happens when the manure used has proved 
unsuitable to the land or to the crop, or there m»y not 
have been enough applied, or there may have been too 
much. 
Coffee supplies will ttand 4 cwt. per acre of Ammonia 
Sulphate uuder favourable conditions of weather, but 
8 owt. is too much, it kills them off. Under like coudi- 
tions 5 tons of callh manure (first quality) answered 
well, but 10 tons was almost as bad ae 8 cwt. of Ammonia 
Sulphate. This shows that oven cattle maunre 
muHt be used with diserotion. It is deservedly a 
faYourito ; it 'a like a charge of snipe shot, it covers a 
wide area, and has less chance of missing tha mark 
than such a manure aa hindy, i. e. oil cake; in which 
the ammonia preponderates so greatly over the other 
mauurial elements; this sometimes like a bullet misses 
its billet; 
