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April 17, 1873] 
NATURE 
463 
nicians are blocking the road to prehistoric research, as the 
Hebrews formerly did. Hype CLAkkE 
32, St. George’s Square, S.W. 
Earthquake Waves 
THE observations at p. 385, on the operation of self-resisting 
tide-gauges of the U. S. Coast Survey, in illustrating the pheno- 
mena of earthquake waves, suggest the expediency of the same 
means being adopted in the basin of the Mediterranean. This 
could possibly, by a little correspondence and agitation, be 
effected at Naples, Athens, Constantinople, and Alexandria. 
The Turkish and Egyptian Governments are very likely to 
listen to any representations on behalf of the cause of science. 
Although the Mediterranean is considered tideless, there is a 
daily fluctuation of two feet in parts of the Levant, but what is 
material is that earthquake waves are known to have been mani- 
fested at Smyrna, 
If our Government could be induced to encourage observa- 
tions at Gibraltar and Malta, we should obtain a combination of 
points of contact for two allied regions. 
4 HypDE CLARKE 
Spectrum of Aurora 
I wisH to make a correction with reference to my observations 
on the spectrum of the aurora, as given by J. R. Capron on 
p. 182; for he has credited them with greater accuracy than they 
profess to have: I have no doubt that my line No. 5, seen at 
wave-length 500 or 510, is the same as Lord Lindsay’s and 
Elger’s No. 4, and probably as Procter’s. This is the more 
likely, seeing that the two former placed the principal line much 
nearer fhe red end than I did ; for I assumed Angstrém’s position 
(5567) to be correct. This leaves but one observer of No. 5 
(Barker), and possibly his line also is the same; in that case his | 
No. 4 will be the same as Lord Lindsay’s No. 3. 
I have seen published the following determinations of the 
positions of the auroral lines, in addition to those J. R. C. has 
given :— 
Wave- 
length. 
Monro dks) Jilleny (5 se. TERR Te 035 
No. 2. O. Struve ek) + ise T° 5545 
ABESHEOM. is) 05 + REE ren % 5567 
German North Polar expedition . zi fa) uh) SOD 
Peirce (as reported by Winlock). ns Dy 
REspIgny ~ s . fs ouget ce! at 
RJ. Bllery. ..... ....> oe se S00 
No. 3. Peirce has two lines near here—5315 and 5205 ; the latter 
is probably Lord Lindsay’s ‘‘line near E,” and possibly A. 
Clark, Jun.’s line also. 
Wave- 
length. 
NoG: berce << + « «) 0) MMOs oc a. AOA: 
No. 7. Peirce os ABI 
Peirce also gives lines at 545 and 486. 
My latest determinations from my own observations are as 
follows :— 
Wave-length. 
606 
566 
- 5165 
» 5015 
4625 
S16) > ee 4305 
I have never seen a line at 532 again. 
As to the continuous spectrum, it reaches from No. 2 to No. 
"7, being brightest from a little beyond No. 2 to No. 6. This 
part of the spectrum does not give me so much the idea of a 
true ‘‘continuous spectrum broken up by dark bands,” as of a 
-series of bright bands too close to be distinguished. 
Sunderland T. W, BACKHOUSE 
s 
SAPO NH He 
Spectrum of Nitrogen 
‘IN a paper communicated to the Royal Society by Mr. 
‘Arthur Schuster, it is stated that the line spectrum of nitrogen 
“may be obtained under all pressures and temperatures if every 
trace of oxygen be removed by heating sodium in the vacuum 
“tube. 4 
I should be glad to learn whether any of your readers have 
successfully treated Mr. Schuster’s experiments, 
My friend, Mr. Lee, and myself have, on several occasions, 
attempted to do so, but always without success. 
On heating the sodium we invariably find that an increase of 
pressure takes place from the liberation of hydrogen which, 
although very greatly lessened, is not entirely removed by drying 
the gas with sulphuric acid. On again exhausting we obtain, 
with the simple current, a spectrum of lines, not of nitrogen, 
but, in every instance, those of the second so-called hydrogen 
spectrum first described by Plucker, and afterwards noticed by 
Wullner and Angstrém. 
This spectrum disappears as soon as the Leyden jar is used, 
and only the ordinary hydrogen spectrum is then visible. 
The only effect which the sodium appears to produce is the 
liberation of hydrogen ; for the same line spectrum can be ob- 
tained by exhausting a tube filled with hydrogen, or even with 
unpurified atmospheric air. 
T was struck by the fact that only a few of the lines given by 
Mr. Schuster in his table of wave-lengths coincide with those of 
the known spectrum of nitrogen, while many of its most brilliant 
lines, including that which is its chief characteristic, the double 
green line (wave-length 5005-5002, Thalen) are not represented 
in his spectrum. 
That the line spectrum of nitrogen can be obtained at all 
pressures, has been shown in a paper by Mr. Lee and myself, 
which has been scnt elsewhere for publication; but that it can 
be obtained at all temperatures, by which, I presume, Mr. Schus- 
ter means either with or without the Leyden jar, is certainly 
contrary to our experience. 
Liverpool C. H. STEARN 
Instinct 
The Heredity of Instincts 
THE following may perhaps serve as a contribution to the 
question so much discussed of late concerning the transmission or 
acquirement of likes and dislikes amongst the lower animals. It 
is ‘an extract from a letter of a brother of mine, an officer in 
India :— 
“‘T have at present a little tiger-cub, about the size of a 
spaniel, a most interesting pet, though it will soon be a dan- 
gerous one. He made friends at once with my fox-hound 
puppies, and romps with them incessantly. When he sees a 
cow ora goat his real nature betrays itself, He has no fear 
whatever of any dog ; but, strange to say, is thrown into a parox- 
sm of terror at the sight of a kitten or a tiger-skin,.” 
This hardly seems to bear out the assumption so commenly 
made, that manifestations of this kind must have a history in the 
experiences if not of the animal itself, at least of its ancestors. 
We can hardly suppose the parents of this cub to have adopted 
a frame of mind respecting the race of tigers equivalent to mis- 
anthropy amongst ourselves, and the experience of cats or kittens 
must be small indeed in the jungles of the Decan. 
St. Asaph, N. Wales Je G. 
Sense of Direction 
In Mr. Darwin’s article in Nature for last week there is a 
passage about ‘‘ the sense of direction being sometimes suddenly 
disarranged,” that brought to my mind assertions I had frequently 
heard made when travelling some years back in the wild parts of 
the State of Western Virginia, It is said that even the most 
experienced hunters of the forest-covered mountains in that un- 
settled region are liable to a kind of seizure; that they may 
| ‘lose their head” all at once, and become convinced that they 
are going in quite the contrary direction to what they had in- 
tended, and that no reasoning nor pointing out of landmarks by 
their companions, nor observations of the position of the sun, 
can overcome this feeling ; it is accompanied by great nervous- 
ness and a general sense of dismay and ‘‘upset ;” the nervous- 
ness comes after the seizure, and is not the cause of it. I was 
present in a company of hunters when a tale of this ‘‘ getting 
turned round ” was told as a good joke against one of the party 
—a Nimrod of renown—the leading features of which he was 
reluctantly obliged to confess to the truth of, while denying some 
minor points that had been added to embellish it, as making him 
more ridiculous than he was : it would take up too much of your 
space to tell the particulars of the story. The feeling is described 
as sometimes ceasing suddenly, and sometimes wearing away 
gradually. Would it not be strange if it should appear that 
there is a ‘sense of direction” other than an acquired sense of 
