22 Wi TOLLE 
‘(as I do) dissent from some of his conclusions; but the 
methods he has used are legitimate and sufficient for his 
immediate purpose, and, in my opinion, the work as a 
whole is one of the most stimulating contributions to the 
~study of intra-racial heredity published in recent years. 
December 22, 1903. G. Upxy YULE. 
WitH regard to Mr. Yule’s view that there is a funda- 
mental misunderstanding in our notice of Prof. Johannsen’s 
book, we must direct attention to the problem at issue 
summed up in the words “‘ Der Riickschlag ist vollkommen 
ganz bis zum Typus der Linie.’’ The character selected for 
measurement by Prof. Johannsen either fully determines the 
type or it does not, i.e. in the latter case it may be subject 
to somatic variations having no influence on offspring as 
Mr. Yule suggests. If it does determine the type, then the 
correlation between the parent and the mean of the off- 
spring should be perfect, and this it certainly is not. If it 
does not determine the type, the correlation might be im- 
perfect because the character of the line would not be 
perfectly known. But since the parental character is in 
this case not perfectly known, it is clearly impossible for 
Prof. Johannsen to determine the type, and thus his experi- 
ments must fail to show whether the ‘* Riickschlag ’’ is 
perfect or not. This point is referred to in the reviews 
cited by Mr. Yule, but it seems to have escaped his notice. 
In the next place Mr. Yule asserts that Prof. Johannsen 
has shown that the intensity of heredity between the first 
two generations sprung from a single individual may be 
vanishingly small. This is precisely what he has failed to 
do. To deal with heredity the same character must be 
selected in two successive generations, and this, as pointed 
out in the review in question, Prof. Johannsen has not 
attempted. 
The remainder of Mr. Yule’s letter being neither a 
reasoned defence of Prof. Johannsen’s book nor a criticism 
of our review calls for little comment; it will command 
from the reader just that degree of assent which he may be 
accustomed to give to mere opinion very authoritatively 
stated. Mr. Yule’s estimate of the value of Prof. 
Johannsen’s experiments and statistical methods differs 
widely from that expressed in our review, but nothing is 
gained either in criticism or controversy by the mere posing 
of a rival ipse dixit. THE REVIEWER. 
The Heat of Radium. 
A NUMBER of years ago I published a theory of the form- 
ation of the elementary bodies, based on polymerisation and 
its reversal. The numerics (‘‘ atomic weights ’’) of the 
elements show an increasing accordance with that theory 
as time goes on. 
Of our existing system of numerics the polymerisation 
points are comprised in the expression n15; they are, 15, 
30, 45, 60, 75, 90, 105, 120, 135, 150, 165, 180, 195, 210, 225, 
240. As chemical change in general exhibits a great 
tendency to run down, we may fairly assume that most of 
the earlier reversals have already occurred, and that such 
as remain will be associated with elements of high numeric. 
It is clear that polymerisation must involve the emission 
of heat, and I am strongly disposed to regard radium 
(Ra= 225) as the product of a ‘“‘stoff’’ in the act of poly- 
merisation, the reversal being well indicated by the dis- 
charge of helium (He=4). § 
It is interesting to notice that Sb (=119-5) and Sm 
‘(=149-9) are extremely near polymerisation points. It would 
be worth while to examine compounds of these bodies for 
emitted heat and gaseous or other matter. 
The emanation phenomenon would also appear to be in 
some way related to the same points. It is, for example, 
stronger in V (+238) than in Th (=231-7). Both these 
bodies, and the substances they emit, should be derived 
from a hitherto unknown polymer (=240) undergoing 
reversal into simpler bodies. : Epmunp J. MILts. 
January 4. — i 
Rocket Lightning. 
My attention has been directed to a letter in your issue 
-of October 22, 1903, describing certain flashes of lightning 
that were visible on July 22. In many respects the flashes 
corresponded with flashes seen by myself and friends at the 
same hour on the same evening, but the discrepancies are 
remarkable. For instance, Mr. Everett, in the letter referred 
NO. 1784, VOL. 69] 
[JaNuARY 7, 1904 
to, saw flashes ‘‘ bearing a strong resemblance to ascending 
rockets, a luminous trail shot up about as fast as, or rather 
faster than, a rocket,’’ whereas we saw flashes that appeared 
with about the ordinary rapidity. There certainly was a 
strong suggestion of ascension, but vertical lightning flashes 
quite commonly exhibit this appearance, which sometimes 
at least is due to an optical illusion. 
The bearing of the flashes as seen by us, from the verandah 
of a house in Camac Street, was N. 143° W., and as the 
Sibpur College bears, from our position, N. 86° W., about 
16,500 feet distant, it would be quite easy to calculate the 
position of the flashes if Mr. Everett had noted their bearing 
accurately. His description of the bearing as “in the 
S.S.W.’’ suggests that this is only intended as a general in- 
dication of the direction. If S.S.W. were the exact direc- 
tion, the flashes could only have been 103 miles distant from 
Mr. Everett and 12 miles from us, but if the direction were 
the next point of the compass, $.W. by S., the flashes were 
59 miles away. This greater distance is probably nearer the 
truth, because if the flashes were only 10 or 15 miles distant 
thunder would have been audible. 
Again, the angular altitude of the highest part of the 
flash is given by Mr. Everett as ‘‘ 15° or so,’’ which does 
not agree with our observation of 10° or a trifle under, 
perhaps nearer to 9°. At a distance of even 30 miles there 
should have been no observed difference of maximum altitude 
between Mr. Everett’s observation and ours. 
In other respects the observations tally precisely. The 
vertical flashes appeared repeatedly in the same position 
against a background of clear sky, so clear that a star, 
¢ Centauri, was visible at an altitude exceeded by the flash. 
Mr. Everett falls into an error in supposing that the 
lightning ‘‘ must have occurred at a spot above the Sunder- 
bunds.’’ The direction of the Sunderbunds is not westerly, 
but easterly from the Sibpur College, and the flashes must 
have been over some part of the Twenty-four Perganas if 
not more than 25 miles away, over the Midnapore district 
if more than 35. 
As to there being ‘‘ not a score of men in all Bengal who 
would take a serious interest in such lightning if they did 
happen to see it,’’ I am not aware of the precise number, 
and can only vouch for three, the manager of a railway, 
another competent observer, and myself, who observed 
together, but I should not be surprised if the flashes were 
also seen by other observers equally able to record their 
observations accurately. W. A. LEE. 
Calcutta, December 10, 1903. 
I Garner from Mr. Lee’s account that he only witnessed 
one kind of lightning, whereas my son’s letter describes two 
kinds altogether different in appearance. The inference 
would seem to be that the less brilliant and more unusual 
kind was not visible in the centre of Calcutta, though visible 
at Sibpur, probably owing to better atmospheric conditions. 
J. D. Everett. 
11 Leopold Road, Ealing, December 30, 1903. 
The Recent Leonid Shower. 
Tue results of the observations by M. Eginitis of the 
recent Leonid shower indicate that there was another maxi- 
mum on the night of November 15, occurring several hours 
previously to that seen by observers situated in or near the 
longitude of Greenwich. This early maximum was evidently 
of a very distinct character at Athens, as the observations 
showed a regular increase and decrease of meteoric fre- 
quency before and after the time of culmination (15—-16h., 
local time), the watch having been prolonged for 
some hours further, or until 17h. som. Athens was 
evidently too far east to permit observers there taking 
cognisance of the later outburst of meteoric activity that 
added considerably to the strength of the shower here. The 
maximum mentioned by M. Eginitis does not appear to have 
been very noticeable as such to British observers, though 
it was anticipated here that that event should occur on 
November 15 at 13h. 30m. G.M.T., the calculated maximum 
thus falling within the hour, when we allow for the differ- 
ence of longitude, during which it was actually observed 
at Athens. The later maximum came altogether un- 
expected. It is noteworthy that these maxima seem to have 
been characterised by quite a distinct type of meteor. 
Dublin. Joun R. Henry. 
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