1824.] 
Salamandra perspicillatra, quinque pal- 
mis plantisque tetradactylis. It has one 
spot on the upper part of the head, 
pretty nearly resembling a pair of spec- 
tacles; but a more striking character- 
istic is, its having four toes on each 
foot. 
M. Marion has found, in the island 
of Manilla, a species of reptile, of the 
family of the Agamoides, which has the 
faculty of changing colour, like the 
cameleon. Its head is triangular, pretty 
large in proportion to the body; the tail 
long and slender; along the ,back, the 
crest or rid is formed of soft scales, and 
under the throat is a goitre. The feet 
have toes detached, and very unequal; 
the scales are mostly triangular, imbri- 
cated, and especially those of the tail. 
The iris is blackish, bordered with a 
little white circle about the pupil. The 
animal is very active, and feeds on in- 
sects. When the author first came into 
possession of it, its colour, for 24 hours, 
was a delicate green, whether held in 
the dark, or exposed to the sun,—whe- 
ther kept motionless, or in a state of 
agitation ; but next morning, on remoy- 
ing it from the inside of a bamboo, where 
it had been placed, its colour throughout 
had changed to carmelite; when ex- 
posed to the air, this colour gradually 
disappeared, and the animal resumed 
its green robe. On this ground, certain 
brown lines were soon after visible: the 
animal was then replaced in the bamboo, 
but, on drawing it out, it had acquired a 
blueish-green colour, and it was only in 
the open air that the brownish tints 
returned; and at length, without any 
variation of form or position, the brown 
colour gave place to a uniform green, 
intermingled, however, with some brown- 
ish streaks. When laid on green or red 
substances, no grain of colour was ob- 
served. 
In ,a Discourse on Volcanoes, lately 
read before the Royal Academy of 
Sciences at Berlin, M. Humboldt re- 
marks, that “ the philosophical know- 
ledge of nature rises above a mere de- 
scription of nature; it does not consist 
in a sterile aggregation of isolated ob- 
servations: it may sometimes be allowed, 
therefore, to the curious and ever-active 
mind of man to look back upon the past, 
toimagine what cannot beclearly known.” 
And under this license, he concludes his 
discourse, by supposing, with Sir H. Davy 
and Laiz Lupac, that the substances 
which melt in the deep recesses of the 
earth, and are thrown up as /ava, “ are 
the metals of the earth, and alcalies,” 
Spirit of Philosophical Discovery. 
iol 
owing to the casual access of oxygen to 
such substances immediately betore an 
irruption; which, we submit, is a sup- 
position by no means agreeing with the 
very. compound nature of the substances 
ejected by volcanos.—And, 2d, he sup- 
poses, that “ the deeply-cleft crust of the 
earth in the primitive world radiated 
heat from its fissures,* sufficient to occa- 
sion “whole countries to produce for 
centuries, palms and arborescent ferns, 
and to sustain animals of the torrid 
zone,” where now frost and snow al- 
most perpetually reign. But, if as seems 
very probable, all the organic beings 
whose remains are really imbedded in 
the strata, and are not found in the re- 
cently moved and superficial alluvium, 
were by their beneficent creator adapted, 
each species to a comparatively short 
period of subaqueous life, or growth, be- 
fore each of such successive species 
became extinct, and every individual 
thereof became buried beneath the next 
created and incumbent stratum, long 
antecedent to the creation of the oldest 
species of being contemporary with the 
first man, as Mr. Favey has long laboured 
to inculcate: if these be tenable posi- 
tions, the above suppositions of M. Hum- 
boldt are alike unnecessary, as they are 
inadequate to account for, the pheno- 
mena which organic remains present 
to us. 
Professor Hansteen, of Christiana, in 
Norway, who has been particularly en- 
gaged in experiments on the intensity 
of the magnetic action, and determining 
the diurnal and annual variations of 
such intensity, as existing on the ter- 
restrial globe, has made public some 
new observations, from which he con- 
cludes, that every vertical object, such 
as a tree, a wall, a steeple, &c., have a 
constitutional relation to the state of a 
magnet. He considers the lower part 
as the boreal pole, and the upper as the 
austral, and observes, that an horizontal 
magnetized needle placed at the foot of 
any vertical object whatever, oscillates 
with more velocity when at the north 
than at the south of the object. And, 
on the contrary, that at the upper ex- 
tremity, 
* The late Sir William Marshall (see our 
46th volume, page 470) in one of his Agri- 
cultural Works, published in 1799, inserted 
some geological conjectures, which are very 
closely allied to those now advanced by M. 
Humboldt, and in 1815 he referred to these 
conjectures in p. 122 of the first volume of 
his “ Review of the Reports of the Board 
of Agriculture.” 
