THE MEDITERRANEAN NATURALIST 
389 
unappreciable effort, educate themselves. This is 
the kind of institution that is now required To 
supplement the utilitarian education which is 
provided by the present system. It would afford 
the means whereby an education would be given 
such as would fit a man for the duties of good 
citizenship ; and it is therefore incumbent on the 
people to see that provision is made for it. 
To cease to provide the means for intellectual 
culture after the boy has taken on himself the 
cares and responsibilities of life is as grave an 
omission as would be the neglecting to provide 
nourishing food to an infant after it had been 
weaned from the mother. 
What the one requires for the making of a ro- 
bust physical framework, the other requires for a 
vigorous mental one. Such an institution as this 
must not therefore be regarded as a luxury; it is 
a necessity. 
Who will supply it? 
Artificially- Coloured Flowers. 
Green flowers have been exhibited in florists’ 
windows in Laris, and have excited a great deal 
of curiosity. The colouring however is not natural. 
A 'Will-known chemical fact is that roses, 
periwinkles, an 1 other flowers are quickly bleach- 
ed in the fumes of burning sulphur; and a French 
chemist discovered nearly twenty years ago that 
a mixture of ether with a tenth of its volume 
of ammonia will instantly turn many red and 
violet flowers— -such as the violet, red geranium, 
red and pink roses, and heliotrope — to a bright 
green, and change flowers of some other colours 
to yellow or black. The flowers now shown are 
colored in a different manner — by liquid absorbed 
through the stems. The process was discovered by 
a florist who carelessly dropped some colouring 
matter into a vase; and it consists in placing a 
little soluble aniline dye in water and immersing 
the stems for twelve to forty-eight hours. When 
malachite green is used, the carnation is turned 
to a deep green, and the narcissus become 
of the same colour. Beautiful pink and blue 
colours may be produced also by using, respec- 
tively, a solution of eosine and one of methyl 
blue. Flowers of certain natural colours are made 
to assume different tints, yellow jonquils being 
transformed by the green dye into greenish 
jonquils of singular appearance, and violet ane- 
mones becoming blue. These beautiful effects — 
capable of brilliant showing in tri-colored bou- 
quets — have suggested that interesting experi- 
ments may be made by applying various colouring 
subtances to the roots of the growing plants, 
when striking results might be expected. 
Petroleum Theories. 
Few unsolved chemical problems have a greater 
interest than that of the formation of petroleum, 
as the discovery of the true origin would show us 
whether this valuable product is being rapidly 
exhausted, or whether, as has been plausibly sug- 
gested, it is still being formed in the earth. Va- 
rious possible solutions have been offered. Men- 
del ejeff supposes petroleum to result from the 
decomposition of an iron carbide by steam, ferric 
oxide and a hydrocarbon being produced; Sokoloff 
from a combination of carbon and hydrogen ; Boss, 
from the leaction of hydrogen sulphide and cal- 
cium carbonate; Daubree, from the decomposi- 
tion of vegetable matter. A later view is that of 
M. Engler, who believes it to be due to the de- 
composition of animal substances. This belief is 
supported by laboratory experiment, as it is pos- 
sible to obtain petroleum by distilling animal 
matter under pressure. 
Resoconto di una escursione 
fatta alle grotte di Isoverde in Liguria 
da Emilio Balbi e A. Card ana Gatto. 
Tra i bei giorni che il Congresso Botanico Inter- 
nazionale di Genova del 1892 ci ricorda dobbiamo 
annoverare quello da noi passato ad Isoverde 
ridente paesello del Liguri balzi Appennini, ove 
il 3 Settembre ci recammo collo intento di esplo- 
