THE TROPICAL AGRICULTUEIST. [May 1, 1901. 
Potatoes,— It takes from 12 cwt. to one ton 
of seed potatoes to plant out an acre, the quan- 
tity depending on whether small set'', large sets, 
or whole potatoes are used — Journal of the 
Jamaica Agricultural Society. 
Many of the Coffee Planters in Southern 
India are going in for rice cultivation, and consider 
it a useful, if not highly remunerative, supplemen- 
tary crop. This is especially the casein the Malnad 
district of the Mysore province. — Indian A(/ricul- 
turist, March I. 
A Correction. — In case anyone may take 
the trouble to notice tlie mistake, I may note 
by the way that, in tlie report, quoted in T.A., 
of my " Curiosities," &c., I am made to say 
Gutta Percha is found in the Amazon Valley. 
I never said so. It is merely one of the vagaries 
of the reporter. Borneo, &c., in the East. 1 said, 
was the home of the (iutta Percha and I think, 
I 'noted tliis on the margin of the paper sent. — 
Old Colonist. 
An Inch of Rain. — What does an inch of rain 
mean? Pew persona have a definite idea. An acre 
if calculated out, will prove to be 6,272,640 square 
inches. An inch deep of water on this acre will 
be aa many cubic inches of water, which, at 231 to 
the gallon, is equal to 27,154 gallone. This immense 
quantity of water will weigh 228,190 lb. or 114 tons. 
One hundredth of an inch ('01) alone is equal to over 
one ton of water to the acre, In forty-eight hours, 
during the month of January, l^-^- inches of rain 
fell at Geraldton. This was equal to 420,837 gallona 
per acre or 1,767 tons, or about one-seventh of the 
total quantity required to irrigate a crop of sugar 
cane during the growing season. — Queensland Agri- 
cultural Journal. 
Botanic Gardens, Natat^.— The rainfall for 
the past year has been 13'20 inches below the aver- 
age of the last twenty-eight years, the total for the 
year being 27 "24 in. as against 88 '03 in. the average 
rainfall at Colombo for 31 years. Many plants 
have died in the Gardens owing to the droughts. 
The climate has been found unsuitable (aa 
shewn above) to t;he growth of cacao (Theohroma 
cacao) though it appears that the fruit of another 
tree called Pac/iira a^6a is sometimes niistaken in 
Natal for that of cacao. The climate seems well 
suited to the cultivation of pineapples, and a long 
extract is given on the question of manures for 
these. The gardens are supported by^subscriptions 
and a Government grant. - Cor. 
Rubber at Manaos.— The Government of Ama- 
zonas has decreed a law that is now being carried 
into effect, and must, like all artificial restraints on 
trade, prove highly prejudicial to the real interests 
of the State itself. Designed to injure Para by 
depriving that city of the great transit trade in 
ruijber, it is likely to react on the rubber industry 
itself, and give rise to a still further fall in prices. 
The advantage of concentrating the export trade at 
one centre, at Para, is evident, as competition was 
always certain to secure the best possible prices f«r 
producers. With two markets, the second at an 
enormous distance from the coast, and with uncer- 
tain telegraphic communication with foreign 
markets, competition by buyers is certain to suffer. 
The decree we refer to obliges all rubber from the 
State of Amazona.s to be landed at Manaos, packed 
in cases, and reshipped at a special wharf under 
Government inspection. —/ri-rfici.rw5&6r' Trades' 
/ournalf March itjh, 
Gbeen Te,^ Manufacture. — Mr, Deane 
reports the following as using his machine in 
Ceylon ; — 
LLST OF OEYLON ESTATES USING DEANE'S PROCESS. 
Brunswick Estate, (2) 
C P Hay ley, Esq. 
E Bosliag, Esq., (Chairman, Planters' Association). 
Ceylon Tea Plantations Co. 
Eastern Produce and Estates Co. (2) 
Messrs. Geo. Steuart & Co. (2) 
Lipton's Limited 
Carolina Estates. 
Darrawella Estate. 
Blessrs. Finlay, Jlauir & Co. (2) 
Hardenhuiah Estte. 
BIkadiia Estate. 
The Hon. .J N Campbell, M.L.C. 
St. Leonard's Estate 
Ratnatenne Estate. 
Messrs. Whit t all & Co. 
CoNiPEEs As Bain Gahges, — According to a recent 
number of the Berne Rorticole, M. Felix Sahut has 
lately communicated to the C'ongres des Societcs 
Savantes observations respecting certain plants that 
act aa registering rain gauges : — •" Mention has already 
been made of the influence of certain more or less 
severe droughts in the French Mediterranean upon 
Pinus Laricio of Corsica, and Cephalonian Fir. 
The lengthening of the branches of these two species 
is always proportionate to the quantity of rain falling 
during those months of the year when it is most 
profitable to them. Co-efficients have been established 
indicating what the degree is for each month of the 
year. These co-efficients enable the relationship that 
exists between the amount of rain fallen and the 
greater or less intensity of the vegetation which it 
iiaa encouraged to be determined. It is shown that, 
under these conditions, it ia possible to judge approxi- 
mately the quantity of rain which has fallen by 
measuring exactly the length of the leader, or of 
the branch produced yearly on these species of pine, 
and, if the estimate is not absolutely proportionate 
to the quantity tf rain registered by the rain-gauge, 
it closely approaches to it ; and a still closer estimation 
miy be made by taking into account the relative 
value of the results produced by rain in the several 
months of the year. It is, therefore, possible, to a 
certain extent, to use plants specially selected for 
this purpose as actual registering rain-gauges." 
The Chemistry of Soil.—" Undoubtedly one 
of the most wonderful discoveries of modern chem- 
istry has to do with the soil," says the Saturday 
Evening Post. " It has been ascertained thac 
the mo3C barren land can be made rich simply by 
adding to it certain mineral elements which cost 
but little. On this basis it is estimated that the 
United States will be able eventually to maintain 
500,000,000 people— more than one-third of the pre- 
sent population of the world. It is merely a quest- 
ion of supplying the requisite quantities of nitro- 
gen, phosphoric acid and potash. The last two are 
readily obtainable at small expense, whereas the 
first may be supplied either by furnishing to the 
soil condensed nitrogen ia the shape of slaughter 
waste, of nitrate of soda ; or by planting clover, 
beans or peas, which have an affinity for nitrogen 
and absorb it from the atmosphere. It ia now 
known that nitrogen is the most important plant 
fo»d, and, inasmuch as chis element composes tour- 
fifths of the atmosphere, the question is merely to 
absorb it into the soil. It has also come to be 
understood that only 2 percent, of the material of 
plants is derived from the soil, the remaining 98 
per cent, being drawn from the air and from water, 
—Bradstrcet's, Feb, 9, 
