October i, 1891.] THE TROPICAL AGRICULTURIST. 251 
ECHOES OF SCIENCE, 
The efffufc of r.diliiig aluminium to steel ingots 
has I'ee^'nily betn di- cucsed by the Amyricju Institute 
cf Mining Engi leer-, and, according to Professor 
Arnold, its elfi c' in rendering slcel castings perftclly 
soun I is very marked. It i- twenty limes as powerful 
as silicoi), aad the result. s eal is tou^her.^ By 
using it, m ingan^se cxn bi discarded, and aconsiJtr- 
ab!e saviug io time ard luel (ffe''ted. 
The new l UiO wliioh recently formed in the hollow 
oF S.ui Diego Cuunty, Ciilifm nia, turns ont to have 
been fed by the Colorado Kiver which, overfluwtd 
its banks owing to thn melting of iUi winter 
snow in the Sierras of Colorado, Utah, and Nevada. 
As evaporation proceeds at I he rate of l';0 inches 
a year in this region, it is expected that the lake 
will only have an ephemeral exi>t'uce. 
In a sUidy of ttie flora of Gr' oaland, Sir J. D, 
Hooker came to iht- couclu-ion that it wn.s Baropean 
rather than American, and Professor E. Warming has 
since tried to show that ir is American lather than 
Buropoau. As usunUy happens in tlie case of t fo such 
coaclusioua the iruth bus iecwesn them, !>nl Professor 
Nathurst now poibts out thatwhilf* the coast of Gree*:- 
land nearest to Iceland conlaina European forms only, 
the ci a^t next to Amsrica yields American torms, and 
at tlie Southern extermity the flora partakes of both 
charHctere. On tlie whole, however, Sir Joseph Hooker 
seema to have been right, the flora being rather more 
"European than American. 
The flora of an insular country comes as a rule 
from the nearest liud, and iu this lespeot is like 
the human population. Thus ia Batain wo have a 
southern florii opp site France, a Germanic flora on 
the east coast, a Lusitanif.n or Pi.-iiinBular flora in the 
south-west, and in the extreme west of England there 
uru two American plants uukoowu in any other part 
01 Europe. Tno seeds have proljably been brought 
hither by winds, tides, or bims; Since the close of 
tho glacial epoch a replnnting of our shores with various 
forms from the nearest coasts has beea slowly going 
on, and is still iu progress. 
According to a German scientific journal the place 
where thunderstorms are most trt quent is Java, which 
has an av rage of no fewer than 97 thundery daya 
in the 5 ear. Next to Jmva C-smes Sumntra with 86, 
then Hmdostan with 56, B orneo with 54, the Gold 
Coa>t wiob 52, and Rio Janeiro with 51. In Europe 
tho li-^t IS hi aded by Italy with 38 days, Austdi with 
23, B.i en, Wurtemberg, and Hungary with 22, Silesia, 
Bavana, Belgium with 21, Holland, Sasoay, and 
Br.iudenhurgh with 17 or 18, France, Austria, and South 
Russin with 16, Britain and 'tbe Swiss Mcjuutaii. s 
with PGveu, Norway with four, and Cairo with three. In 
Eastern Turlcostaa and in the extreme northern parts of 
the world there are lew or no thunderstorms. In fact 
the nortbern limit runs through Cape Ogle, Iceland, 
Novajt Semeija, a' d the coa-t of tho Siberian Sea, 
It is clear from theso sta'islics that htat is necessary 
for the product! .ns of thunderstorms ; henoa it ia that 
they aro most frequent in the hottest summur months, 
Buch as July and AugusN But heat alone is evidentlyuo'j 
ovoryttdng; there must be moisture too, and in the form 
of clouds. Cairo, for instance is a very hot place, bxrt 
bi iug dry and cloudlet-s it is seldom vi-<ited by 1 ghtniug. 
It is wtll-kiionn tlmt a mixture of lime and sulphate 
of copper has bteu used as a germicide in diseases 
of the vine, potato, and tomato. M. Aime Giraid 
hixs also applied this remedy to beetrnots threatentd 
with uttaclcs of the fungus wliich causes the disease' 
known as PeroDospora Schachtii.'' Athree par cent, 
solution of copper uulphate is mixed with a three 
per com. v alcr of lime, and tho mixture is spr'iyed 
on the bi'ct from a tank curried on the dresser's back. 
Copper hydrate is the effective agent, butits use had 
he lor Lo watched with care, for certain cereals are 
knuwu tj asainiil\t3 metallic salts, and beet rugiir is 
now consumed iu Urge qunuiitics by children. 
On the Gth of .)uno last a shov.'cr of stones fell at 
Pel-ot-Dcr ia tho Drpattn:ent of the Aub<i during a 
violent, h.nlntjrm. These unwonted di-ops have been 
cxamiucd by a goulogist, who finds th. m to be of 
ohnlk from Chale;m-Landou, which ia 150 kilometres 
from Pel-et-Der. It is believed that the stones were 
lifted into the atmosphere, and conveyed by a whirl- 
wiud, — CHoht. 
CACAO, COFFEE, AND COCA IN PERU. 
Prom a recently-published report by Couaul Mansfield 
OQ tbe Agricultural (Condition of Peru, datf.d Lima, 
October 8tl;, 1890, we learn something cf the value 
of tho above niimed plants in that country. 
Of Cacao, or Cocoa, as we usually call it i. J'heobroma 
Cicao), we nro told that up to a recent date its 
cultivation in Peru Eeonis to have been confined more 
especially to the Transandir.e slopes, in the province 
of Convencion, in the department of Cusco; not, 
however, in snfiicipnt quantities 10 supply the markets 
of the southern departments of the Republic. Tho 
C»cao produced is of a superior quality, and could 
compete odvantageously with the heat descrijitiona 
r»ised at Soconusoo aiid in Venezuela. The excellence 
of the bean is, however, rather due to the geological 
and topographical conditioras of the Valley of Santa. 
Ana than to the eflorts of the cultivators. The Cacao 
goes by the name of Cusco Cacao, but owing to the 
cost of production, distance from the sea, and deficieucy 
of transport, cannot compete in price with that im- 
ported from Ecuador; consequently, the production 
and consumption doe'* not extend beyond what is 
requisite for the local demand. Cacao of good quality 
has also always been raised iu the province of Jaen, 
in the department of Oaj.imaica, and the cultivation 
of the plant extends towards the sea-board in the 
north of the department of Piura ; but upon so limited a 
scale as scarcely to amount to more than an experiment. 
With a more extended develoiimtnt. Cacao could 
easily be produced iu sufiioieat quiintities for the 
uitferual consumption of Peru, displacing export from 
abroad, and, perhap=i, even competing in foreign 
markets, a future for tho industry which appears 
more than probable, vnhen the contemplated irrigation 
fcliemo iu the department of Piura shall have beeu 
carried into effect. 
With regard to Coffee, it is said no better quality 
is i^roducec; in the world thso in Peru ; more especially 
that raised at Ch&uchamayo, in the department of 
Juuin, and in the province of Carabaya, in the dtpirt- 
ment of Puuo. The ijroduct.ion amply suffices for the 
internal consumption, notwithstanding that tho latter 
has much increased during the last few years. Small 
quantities, during feveral years, have been exported 
to Europe, which, on account of the quiliiy, found 
favour in tbe markeb, and fetched good prices, with 
the result that foreigners are beginning to settle ia 
Peru as Coffee planters upon quite a considerable 
scale. The coast valleys, as well as those iu the 
Tranjandine districts, furnish a favourable field for 
the plantalious. The amount of the present production 
is not estimated. In 1888,27,107 kilos, were exported 
from Oallao, and 25,650 kilos, were imported from 
Gu'yaqui! through the same port. 
The Coca plant (Brythroxylon Coca) eg well known 
for its anesthetic and medicinal properties, is iudi- 
pecous in Peru, and is largely consumed by the 
Indians in the Republic, where it is cultivated for 
exportation. No other country, indeed, competes with 
Peru in the quantity exported. Two establishments 
txist for preparing the leaf — one in Lima and one 
in Callao. During the last year, 1730 kilos, of Cocaine 
were exported to Europe, principally for Germany. 
No statistical data are forthcoming concerning the 
amount of production, hut in the year 1888, 28,660 
kilos, were exported through the port of Callao.— 
Gardeners'' ChroHkle-. 
^ 
" Practical Lanscape Gaedening."— Under this title 
Messrs Putnam, of New York, announce the speedy 
publication of a work by Mr. Samuel Parsons, Su- 
perintendent of Parks iu the City of New York.— 
(hinlencrs' Chrvnidc. 
