October i, 1889.] THE TROPICAL 
AGRICULTURIST. 
277 
were lifted bodily, ' root pruned, as advised by some 
Rosarians, and replanted in a mixture of manure and 
leaf mould after eight months' growth. I find the 
Roses left alone, without trenching or manure, by far 
the most vigorous; those trenched and manured, the 
next best; and those taken up and replanted in rich 
soil the worst as regards both growth and flower. The 
month of May has been unusually rainy and moist, 
and our Roses have been flowering luxuriantly. For 
the last few days heat has appeared, max 74°, min. 60°, 
sky hard blue, sun burning. Most of .th6 Roses are 
withering. Usually the withering of the Roses from 
heat occurs by the 10th of May, when we feel it time 
to depart for pastures new. 
We have an economical but very useful plan of 
using manure ; a handful or more is placed at the 
bottom of the hole where the plant is to be placed, 
and the roots of the latter spread on it. I recollect 
on one occasion, Dr. Hogg paying me a visit, and being 
surprised with the luxuriance of a plant in flower. He 
asked me to allow my gardener to dig it up, and we 
found the roots clinging to and all round the manure 
thus placed, forming, indeed, a ball with it. Thus 
was its luxuriance accounted for in an apparently poor 
soil, I recollect Dr. Hogg being also much struck 
with the extreme vividness of the colour of the flowers, 
which he attributed to the intensity of the sunlight — 
no doubt the true explication. Photographers say that 
the light is four times as intense at Nice, at midday, 
as it is in Paris. 
Under these local conditions, the difficulty of ob- 
taining vegetable mould and manure, and the unmiti- 
gated lime character of the soil, I am gradually 
limiting outdoor cultivation "to lime-loving plants, eli- 
minating such as do not do well in it without any 
alien element. My notion of a garden is for everything 
to succeed, to be vigorous, healthy, happy. I have 
been too much saddened throughout my professional 
career by invalidism and bad constitutions to stand 
them in the garden. All that does not thrive with 
me is rooted up, and made away with. On another 
occasion I shall have something to say about some 
plauts, such as the Linum trygynum, the Russelia 
juucea, &c, which must be lime plants from the mar- 
vellous way in which they flourish with me. 
In conclusion, I would add that gardening on these 
sunny lime rocks overhanging the Mediterranean is 
intensely interesting. I have a small staff of local 
helpmates, into whom I have instilled an interest into 
all we do : so I and my men, we ramble about the 
rocks, make tanks, build walls (uo longer in mortar, 
but in loose stones), dig and delve round the old tower, 
looking for the treasures no doubt buried somewhere, 
hundreds of years ago, by some medieval Italian 
freebooting Captain Kidd, pirate by sea, robber by 
land, who made the tower his stronghold. We have 
not yet found the treasure, but, like the husbandman 
in /Esop's Fables, we fertilise the land. At the time 
of the earthquake, a great facing of rock on a moun- 
tain 1,000 feet above me fell off with a great crash, 
tumbling into the ravine below, and revealing a cavern 
as large as a chapel, in the bowels of the mountain. 
There are mauy such caverns up and down in the 
rocks. So now we are blasting away, in likely directions, 
hoping to find Sinbad the Sailor's cavern, if not full 
of diamonds, at least of stalactites, and perhaps of 
Oapillus veneris, our commonest Fern, should light 
po.ietrate. — Henry Bennet, m. d., Torre di Grimaldi, 
\ < Qtimiglia, Italy, June 1.— Gardeners' Chronicle. 
♦ 
THE WATER REQUIRED FOR RICE 
CULTIVATION. 
WTiat'is the quantity of water required excluding 
absorption and evaporation, but including rainfall, to 
produce the best results in rice cultivation in India? 
Considering the pnorrnous irrigated area in this coun- 
try, and especially that under rice, the question is 
one of great importance. It will be hardly credited, 
however, that it cannot be answered with any pre- 
tence to accuracy. The engineer, it is true, is guided 
by the more or less empirical rule that two cubic 
yards per hour per acre are required, exclusive of 
the rain falling on the area irrigated. The rule has 
not been deduced from scientifically conducted ex- 
periments ; the cubic yards are supposed to be the 
average quantity that the cultivator will dr^w when 
left alone, from his source of supply, whether tank 
or river channel. In fact, at times he uses a great 
deal more than that quantity, and when the supply 
falls low, a great deal less. Observations made from 
time to time have shewn that the amount varies 
from one to four cubic yards per hour per acre. If 
one cubic yard is sufficient, it is manifest that with 
four cubic yards, there must be enormous waste, and 
this in a thirsty country were every cubic yard is 
worth its weight in silver. The ordinary reader will 
appreciate the difference more readily when we state 
that for three months' crops on 10,000 acres a pro- 
vision of over 86 millions of cubic yards would have 
to be made at the higher limit; at the lower 22 
millions only. For a six months' crops the quan- 
tities would be 144 millions, and 36 millions, res- 
pectively, or, in other words, if one cubic yard per 
hour per acre is sufficient to produce a fair average 
crop of rice, 144 millions of cubic yards of water 
would be sufficient to irrigate 40,000 acres in the 
place of 10,000 aores at the higher rate. The im- 
portance then of the question will not be contested. 
We are aware that experiments have been made under 
the orders of Government on several occa-ions, but 
they have not been scientifically nor continuously 
conducted, and they have been far too few in number. 
Deductions made from a few ill-devised experiments 
are worse than useless for they tend rather to mislead 
than to enlighten. Besides they have been entrusted 
to some engineer constantly on the move, whose at- 
tention oould not therefore be continuously given to 
them. The question is one for the agricultural chemist 
rather than for the engineer, The role of the latter 
should be confined to the designing and making the 
works necessary for the accurate measurement and 
distribution of the water required for the experiments ; 
otherwise he should have nothing to do with them. 
Hitherto experiments made in Iudia have erred in 
several directions. The chemistry of the subject has 
been much neglected. No analyses have been made 
of the soils of the plots experimented on nor of the 
manures used, nor of the water supplied; these are 
serious omissions, as wilhout the knowledge such analy- 
ses give, it is impossible to say how much, and what 
manure should be used. In fact an analysis of the 
soil and of the water and its contained slit would 
often indicate that manure was unnecessary, as the 
water carries with it all the nutrient substances either 
in suspension or solution, required for the growth of 
the plant. In parts of Normandy where meadows 
are irrig-ated, it is found when the supply is large 
rising sometimes to what appears to us here in India 
the enormous quantity of 200 litres per second per 
hectare, or 400 cubic ya'-ds per hour per acre, no 
manure is necessary ; when, however, the supply is 
small or deficient, the quantity of manure required 
increases as the water supply decreases. In the south 
of France irrigated land has to be very heavily ma- 
nured, as the supply is often not more than 2 cubic 
yards per hour per acre. French experiments have 
established that the fertilising power of water depends 
upon the volume of water used, within a certain 
maximum limit of course; and that knowing the 
chemical composition of the water, especially the quan- 
tities of nitrogen and phosphoric aoid held in solution, 
and the volume of water available, and comparing 
these with the weight and chemical composition of 
the gathered crops, a balance may be struok, and 
the exact amount of manure required fixed in each 
case. But experiments have made no use for further 
irrigation of the surplus water run off the experimental 
blots. A first irrigation, — we again turn to the French 
experiments, — absorbs about 30 per cent of the nit- 
rogen and phosphoric acid in solution, so that the 
water run off is not so rich as it was, bat is still 
rich enough to be used for further irrigation. Whc. 
we want to know then is, how much surplus flows 
