184 
NA TORE 
[ Dec. 16, 1869 
of Irish existence as to work a gradual change in the 
national character, is a question of much interest, but 
too large to be discussed just now. In any case we can 
scarcely expect the results of centuries upon a national type 
to be reversed in less than a succession of generations. 
Still confining myself to the past, let me point again to the 
very marked qualities which the conditions of their existence 
have produced in the people of the United States. They 
started with a large element of English energy already in- 
grained into them ; they have been reinforced by millions 
of emigrants presumably of more than the average energy 
of the various races which have contributed to swell the tide. 
Added to this, the Americans have enjoyed the natural 
stimulus of a practically unlimited field for colonisation. 
Only the resolute, self-reliant settler could hope to 
prosper in the early days of their national existence ; and 
self-reliance approaching to audacity is the special type 
of character which on the Darwinian hypothesis we should 
expect to see developed, transmitted, and increased. 
How far this accords with actual experience, no one can 
be at a loss to say. There is probably not a nation in the 
world whose peculiarities might not be traced with equal 
ease to the operation of the same universal principle. 
And the moral of the investigation is this: Whenever a 
law is sufficiently ascertained to supply a full explanation 
of all past phenomena falling within its scope, it may be 
safely used to forecast the future ; and if so, then to guide 
our present action with a view to the interest and well- 
being of our immediate and remote descendants. Read by 
the light of Darwinism, our past history ought to solve 
a multitude of perplexing questions as to the probable 
supremacy of this or that nation in times to come in the 
field of commerce, as to the effects of emigration and im- 
migration on the ultimate type likely to be developed in 
the country that loses and in that which gains the new 
element of national life, and many another problem of no 
less interest to ourselves and to humanity. 
The subject I have thus slightly indicated seems to me 
to deserve a closer investigation than it has yet received : 
and, strange as it will sound to the ears of politicians, I 
cannot doubt that, in this and other ways, statesmen, if 
they could open their eyes, might derive abundant aid 
from the investigations of science, which they almost 
uniformly neglect and despise. isl 
THE PROGRESS OF NATURAL PHILOSOPHY 
[We have been favoured by Professor Tait with the following 
extracts from his Introductory Lecture to his class at Edin- 
burgh University, the object of the Lecture being ‘‘to show 
that Natural Philosophy is a vea/ science, as tested by steady 
growth and progression, compared with other so-called 
Philosophies, which have periodic cycles, and come back 
after a generation or two into the old, old groove, with the 
same old rope of sand to be spun over again.’’—ED. ] 
O enumerate in detail all the advances effected in 
natural philosophy during even the past year would take 
more time than is usually devoted to a lecture, so that I 
shall confine myself to a mere mention, not exposition, of 
a very few of the more interesting discoveries in cosmical 
science which have recently been made. 
First. We have obtained an immense amount of new 
information as to the constitution of the sun. The total 
eclipse which was visible in India in the autumn of last 
year, was singularly well fitted for applying to the strange 
phenomena of the sun’s atmosphere the comparatively 
novel powers of the spectroscope. Another total eclipse 
has recently been carefully observed in America, and the 
results obtained on these two occasions agree well with 
one another. 
One of the most marked phenomena observed in a total 
solar eclipse is that which, first carefully described some 
thirty years ago, was called the “red flames ;” very sin- 
galar protuberances issuing apparently from the dark 
body of the moon, but which were conclusively proved in 
1860 to belong to the sun. Had they been lunar pheno- 
mena, their dimensions would have been considerable ; 
but it is easily shown that, belonging to the solar atmo- 
sphere, their dimensions are evormous, a hundred thousand 
miles being often no exaggerated estimate of their diameter. 
They must evidently be masses of extraordinary tenuity, 
else they could not rest in the solar atmosphere, which 
must be excessively rare at such an elevation. When the 
spectroscope was directed to them last year, it was at once 
perceived that they are fiery clouds, consisting mainly of 
hydrogen gas, heated so powerfully as to become self- 
luminous. This discovery once made, the total eclipse 
was seen to be unnecessary, and observations of these 
singular phenomena are now carried on every day. In 
fact, in anticipation that such would prove to be their 
nature, they had actually been sought for before the date 
of the eclipse. The reason why we can see them, in spite 
of the comparatively overwhelming light of the sun, is 
simply this, that the sun’s light, which may be said roughly 
to consist of rays of all degrees of refrangibility, can by a 
sufficient number of prisms be spread over any desirea 
extent, and thus weakened throughout; while the light 
from the red flames consists of but a few perfectly homo- 
geneous rays, which may be indefinitely separated from one 
another, but cannot be individually weakened, by increasing 
the power of the spectroscope. The process, in fact, 
closely resembles that by which, with powerful telescopes, 
astronomers are enabled to observe stars in the day-time. 
The powerful telescope diminishes the apparent brightness 
of the sky; but the star has no sensible diameter, and 
remains undimmed. A singular fact observed is, that 
while the bright rays in these red flames, which are due to 
hydrogen, correspond exactly to well-known dark lines in 
the solar spectrum, due to absorption by the sun’s atmo- 
sphere ; there are others, especially a curious one in the 
yellow, which have no counterpart among the dark lines. 
Also the hydrogen lines are sometimes broader, some- 
times narrower, than the normal spectrum of incandescent 
hydrogen requires ; sometimes they are slightly displaced 
from their normal positions in the spectrum, The explana- 
tion (on purely physical grounds) of all these phenomena 
is now being carefully sought, and the connection of the 
red flames with sun-spots, as well as the singular pecu- 
liarities of the spectra of spots, are being recorded for 
future explanation. In this one direction alone a field has 
been opened up for inquiries which, eyen with our present j 
appliances for observation, may well occupy the world for 
a generation to come. 
Another striking phenomenon of a total solar eclipse is 
the (so-called) Corona of whitish light which appears 
to surround the dark body of the moon to a considerable 
angular distance. This also has been proved to belong | 
