tHE TROPICAL AGRICULTURIST. 
786 
is bvoVTght about and very soon we find 
that the growth of the plant is arrested. This is 
exactly what happens here in dry weather. We 
are apt to attribute the want of growth to 
want of water for the plants. But we forget 
that if it was actual want of vaterfor the plants, 
the leaves of the latter would fade and drop off. 
The true explanation is this. We know that 
plants act like pumping machines. By 
their transpiration they throw back into the at- 
mosphere the water that has fallen to the ground ; 
they cause the soil to dry up, and with the drying up 
the conditions favorable to the performance of the 
functions of these micro-organisans disappear. At 
this stage even the largest provision of nitrogen 
fails to do any appreciative good, since the micro- 
organisms are unable to perform their function 
of converting the nitrogen into nitrates, the form in 
which nitrogen is taken up hj' plants. There- 
fore, before these large and expensive applications 
of nitrogenous manure.s are resorted to, which 
we have seen may be superffuous at one time and 
useless at another, would it not be well lir.st 
to attend to the conditions required by these 
micro-organisms ? This can be ilone by increas- 
ing the absorbing and retentive p'owers of tlie 
soU for water. The planter bas already recog- 
nised this necessity by keeping the soil free from 
weeds, those powerful evaporators of water. He 
ought now to go a step further (which some have 
gjlready done,) and loosen the soil, either by turn- 
ing, forking or cutting holes and lilling them in 
again, in order to increase the capacity of the soil 
for holding water and - to facilitate the circulation 
of air containing the oxygen, which is another 
condition necessary to sustain the functions of 
these micro-organisms. A soil thus worked has 
been found to generate a.s much as three times the 
to amount of nitrates produced by a soil left itself. 
But there are yet other means at the dis- 
posal of planters to preserve moisture in the soil. 
I have said already that plants may be looked 
upon as powerful pumping machines. It has 
been found that plant leaves often transpire in 
the space of one hour as much as their own 
weight in water and that generally they transpire 
from 233 to 912 lb. of water for every pound 
of i»lant tissue formed. Wliat this means everybody 
can lind out by multiplying this amount 
by the weight ol leaves removed by crop. This 
transpiration has been found to be regulated by 
the amount of plant-food in the soil. Thus whereas 
a plant with a sufficient amount of nourishment 
in the soil transpires 2.50 lb. of water for -every 
lib. of plant tissue formed, the same plant trans- 
jdres SOU lb. of water when left to grow in pom- 
soil. It is clear therefore what an advantage it 
is to keep the plants liberally supplied with 
properly constituted fertilizers in order to prevent 
exces.sive transpiration and thus to keep the 
moisture in the soil where it is needed during 
the dry months. 
The sooner tlie planter realizes the fact that 
nitrogen is not the food for plants but nitrate.s, 
the formation of which is dependent upon the 
function and activity of mioro-orgaiiisms and that 
lie will liave to look to the conditions^ of life for 
tlie latter in order to get tbe^ benelit of the 
former, — the sooner will he arrive at a, due ap- 
preciation of what constitutes soil fertility and 
the better will lie be able to mnke bis culti- 
vation pay. — 1 am, dear sir, yours faith- 
fully, 
A. BAUK, 
The Ceylon Manuring Works. 
[May 2 , 1898 . 
CAMPHOR CULTIVATION IN CEYLON 
Government Botanic Gardens, Hakgala, 
Nuwara Eliya, 6 ih April, 1-98. 
Dear Sir,— Relerring to your question as to 
wliat is being done with camphor cultivation in 
Ceylon,! may add the following to what 1 wrote you 
on' the lltli of February last. Wishing to sati.sfy 
my.self that solid camphor exi.sted in the leaves 
and twigs, of even very young plants, L sent a 
small bundle of prunings, from plant.s ])k.nted 
out at the end of 189-5, to Mr. f>. A. Owen of 
Messrs. W. Jordan & Co. of Lindula, who had 
very kindly undertaken to make the experiment 
for me. I am pleased to state that lie has 
been very successful in extracting solid cam- 
phor from them ; and as this of general in- 
tere.st to planter.^, 1 shall he mnclt obliged if 
you will be good enough to publish Mr. Owen's 
letter in an early issue of your paper. 
The i>runings from an average plant 28 
months ohl as grown here, weigh from 10 
to 12 lb. 
I have a good manj^ plants that want prun- 
ing, and if ap))lied to before the eml of this 
month, April, I shall be very glad to .sup|dy 
iU or 20, or 35 lb. prunings to any person wish- 
ing to make the experiment for himself. — I am, 
dear sir, yours faithfully, W. NOCK, 
Superintendent, Government Botanic Gardens, 
Hakgala. 
The following is Mr. Owen’s letter, Talawakele, 
March 30th, 1898. 
Dear Mr. Nock, — Thanks for the parcel of camphor 
prunings duly received. I have made several experi- 
ments. The following is the account of meth-rds em- 
ployed and results. 
(1) Took about 7 lb. of mixture of leaves, twigs 
and small branches and gently simmered with about 
2 gallons of water for 3 hours. Result : a strong 
smell of Campor pervaded the bungalow and a small 
quantity of Camphor Oil collected on the surface of 
the water but no solid Camphor appeared. 
(2) Selected the thickest of the branches (averag- 
ing about an inch in diameter) and cut these into 
small pieces about 4 lb. in all. These chips were put 
into an empty kerosine tin, and this tin was placed in- 
verted over another kerosine tin partly filled with 
water and the joints between the two were luted 
around to make it steam-proof. The upper tin had 
a circular hole cut into the top part, omd this hole 
was fitted with a cork and the cork was provided 
with a glass tube about 2 feet long commuuicating 
with a condenser. Heat was applied to the lower tin 
and soon after water beg.ui to boil, solid Camphor 
commenced to form in the tube and a little while 
after the latter became blocked. The f-team now 
forced a passage through the various joints and 
so the remaining Camphor was carried into the air 
thus spoiling this tri-al. 
(3) A gallon iron kettle was packed with leaves 
and small twigs together with about 2 pints of v/ater. 
The cover of the kettle was luted on and the spout 
fitted with a cork, while a long glass tube proceeded 
from the cork to a condenser, A short time after the 
step.m commenced to flow, solid Camphor began to 
form in the tubu until the hitter -w-as at length blocked 
to a considerable distance ; there was in consequence 
a loss of Camphor as in previous experiments, but 
not so much as the tube was cleared by the application 
of a spirit flame which caused the Camphor to 
melt and run down. As tlie result was so 
promising I determined to caix-y out the same 
e.-jpen'men!, with a definite quantity of material, 
as belov/. 
( jj Packed the kettle with 1^ lb. of leave.s and 
twigs as before with same amount of water and 
modified the arrangement so that no blocking could 
occur. Applied heat gradually and kept it up for five 
hours. At the end of this time the sides of the 
April 23. 1898. 
