246 
NATURE 
G. Krebs (pp. 439 to 448). The author describes experiments, 
with tiresome fulness of detail, in proof of the fact that the pres- 
sure upon water which has been long boiled may be reduced 
considerably below the maximum tension of aqueous vapour at 
the temperature of the water, without ebullition taking place ; 
but if, under these circumstances, a further sudden diminution of 
pressure takes place, or if the water is heated, very rapid or 
even explosive ebullition is liable to occur. 
(4). “Lightning without Thunder,” by Prof. Th. Hoh (p. 496). 
In the night between the 25th and 26th July, the author observed 
Jorked lightning unaccompanied by thunder. 
The other papers in this number are: “ Investigation of Mica 
and allied minerals,” by M. Bauer (pp. 337 to 370); “Studies of 
the oxygen-compounds of the Halogens,” by Hermann Kammerer 
(pp. 390 to 417) ; “ Mineralogica! Communications” (eighth part), 
by G. von Rath (pp. 449 to 496). 
BOTANY 
The Diffusion of Plants 
Pror. DELPINO, of Florence, has published some interesting 
researches on the relation between the diffusion of plants and 
animals. The life of every plant has three principal objects: 
its nourishment, its reproduction, and the distribution of its 
seeds; for each of these three objects special bio logical con- 
ditions being requisite. The fertilisation of many plants can be 
effected only by some particular animal; as Avzm italicum, 
Aristolochia, and Asarum, by gnats; the fig tribe by different 
species of Cyzifs (or gall-fly); Arum dracunculus, Stapelia, 
and Rafflesia, by blue-bottle flies ; many others by different kinds 
of flies or bee-like insects (//ymenoptera), and some even by 
small birds belonging to the family of 7yochilide, or humming- 
birds ; Rosa, Paonia, and Magnolia grandiflora, by beetles of the 
chafer tribe ; others again by small slugs. If in any particular 
locality the animal necessary for the fertilisation of a particular 
plant is absent, it is certain that the plant cannot spread ; and 
thus the conditions for the diffusion of plants are dependent on the 
geographical distribution of animals. A remarkable illustration 
is furnished by two plants belonging to the saine genus, grown 
in-the botanic gardens in Italy, Lodelia syphilitica and L. fulgens ; 
the flowers of the former are abundantly visited by Bonzdres Lex- 
vestris and italicus, and freely produce seeds; the latter, not- 
withstanding its beauty and its great store of honey, is never 
visited by insects in the neighbourhood of Florence, and never 
bears seeds spontaneously, but can be readily fertilised by artifi- 
cial impregnation. Prof. Delpino conjectures that it is naturally 
fertilised by humming-birds. He believes that the scarlet colour 
of the corolla, so common in the tropics, but comparatively rare 
with us, is especially attractive to small birds, but offensive 
rather than otherwise to Wymenoptera. Asa rule, scarlet flowers 
are large, bag-like in form, horizontal in position, and with the 
nectar completely separated, which would of itself perfectly pre- 
yent their fertilisation by insects. The largest European flowers, 
such as the peony and large bird-weed (Convolviulus sepium) are 
fertilised by sphinxes and rose-chafers. [Botanische Zeitung. ] 
The Victoria Regia 
THIS magnificent plant has thriven to an unprecedented degree 
during the past summer in the Botanic Gardenat Ghent. Several 
leaves haye attained a diameter of nine feet, and have supported 
a weight of 250 lbs., and one even the enormous weight of 
500 lbs. Seven of the gigantic leaves completely covered the 
basin of 164 feet square, and they were obliged to be removed 
to make room for the young leaves which continued to develop 
in the centre. Every four or five days a fresh flower appeared, 
which Jasted only two days, or rather two nights, opening in the 
morning of a perfectly white colour, diffusing about five or six 
P.M. a very powerful odour of vanilla, closing the next morning 
at 8 or 9 A.M., opening the same day towards evening, this time 
of a beautiful carmine, and finally closing the next morning. 
The magnificent leaves last through the summer; the plant 
begins to dwindle in October, and diés towards December. 
About this time the seeds, which have been obtained by artificial 
fecundation, arrive at maturity. They are sown in January, and 
appear above the ground in about six weeks. Their infancy is 
yery critical ; but once past this period, the young plants grow 
with astonishing rapidity; the plant in the Ghent Botanic 
Gardens, unquestionably the finest that has ever been cultiyated, 
arrived at its full development in five months, : 
CHEMISTRY 
Lenz on Electrolytic Iron 
Tue remarkable results of Graham’s experiments on the 
occlusion of gases have induced Lenz to examine the relation ot 
galvanically-deposited iron to this important function. With the 
aid of a Sprengel pump and apparatus differing but little from 
that employed by Graham, he has arrived at the following 
conclusions. Iron and copper, prepared by the reducing action 
of a galvanic current, contain gases, hydrogen more especially. 
The volume of the gas absorbed by iron varies within very wide 
limits, but may amount to 185 times the bulk of the iron, to the 
surface of which its presence is principally confined. The gas 
extricated from such iron, at temperatures under 100°, consists 
almost solely of hydrogen. 
MINERALOGY 
Des Cloiseaux on Gadolinite 
THIS rare mineral has been studied by different crystallo- 
graphers with apparently contradictory results. Haty, Phillips, 
Lévy, Scheerer, and Waage have included it in the clino-rhombic 
system; Miller, Nordenskiold, and Von Lang regard it as ortho- 
rhombic. The question could not be definitively settled by angular 
measurements, inasmuch as the primitive prism is a limiting 
form, bearing upon the corresponding elements of its anterior 
and posterior portions modifications whose incidences only differ 
by a few minutes. The author showed in 1860 that some species 
[Dec. 30, 1869 
of gadolinite are mono-refractive, some bi-refractive, and some are | 
mixtures of those two kinds; but it was not until the summer of 
last year that he was able to accumulate sufficient material for an», 
exhaustive investigation. It now appears (1) that the Hitterde 
crystals measured by Waage and the author, and analysed by - 
Scheerer, have an energetic bi-axial refraction on two optic axes 5 
the orientation of these axes, that of their bisectrix and their 
inclined dispersion, prove that the primitive form is an oblique — 
rhomboidal prism, whose plane of symmetry is the same as that 
of the axes: this variety contains 10 to 12 per cent. of glucina. 
(2) The most homogeneous of the Ytterly crystals, measured by 
Von Lang and analysed by Berlin, are mono-refractive ; they 
exhibit a certain number of peculiar modifications, in addition 
to those shown in the Hitterde crystals, of which they are the 
pseudomorphs; and they do zo¢ contain glucina. (3) The hetero- 
geneous specimens are forms in transition from the first to the 
second variety; they contain from 2 to 6 per cent. of glucina. 
These three kinds of gadolinite differ entirely in their symbolic 
chemical relations. The bi-refractive kind has the formula R,Si; 
the mono-refractive is a sort of peridote, R, Si; and the transition 
forms give an undecided result, the ratio between the oxygen of 
the silica and that of the bases varying from 3:4 to 4:5. These 
differences of constitution probably originate in local cireum- 
stances. The Hitter6e mineral seems associated with malacon 
and polycrase, in a granitic vein composed of quartz, orthose, 
and oligoclase (with a little mica), and crossing the “ gabbro”” of 
which the greater part of the island of Hitteroe is formed: but 
that of Ytterby is chiefly accompanied by yttrotantalite and 
fergusonite, and imbedded in a red lamellar orthose, divided by 
large plates of black mica. [Ann, Ch. et Phys. (4) xviii. 305.] 
ZOOLOGY 
Development of Sacculina ; 
In a note, published last February, on the development of the 
egg in those curious crustacean parasites, the Sacculing, M. | 
Gerbe stated that the ovules of these animals are formed at first 
of two transparent vesicles or cells, each furnished with a~ 
nucleus and a common membrane; that one of these cells 
enlarges considerably, and that at the maturity of the ovum, the 
large cell in which the elements of the vitellus have been 
developed predominates to such an extent that the smaller one 
forms only a minute prominence at one pole of the ovum. M. 
Gerbe compared the large cell to the yolk in the eggs of birds, 
and regarded the small one as representing the germ or cicatri- _ 
cula. This homology was also applied by him to the ova of the 
Arachnida and Myrtopoda. ; : 
M. E. van Beneden finds that the ovules are not at first com- 
posed of two closely applied cells, but that they form a single 
cell, formed of a transparent protoplasm, containing a few 
strongly refractive globules, and of a vesicular nucleus with a 
nucleolus. 
With these are observed others ofan elongated form, 
