NATURE 
[FEBRUARY 4, 1897 
The Earth and its Story; a First Book of Geology. By 
Prof. Angelo Heilprin. Pp. 267. (Boston: Silver, 
Burdett, and Co. London: Gay and Bird, 1896.) 
THIS is a most attractive little book of geology. It 
presents very clearly the general facts concerning the 
formation, structure and development of the earth ; and 
notwithstanding its popular character, it contains a large 
amount of the more detailed information required by the 
elementary student of the subject. 
Prof. Heilprin begins with the decay of rocks, and 
then describes the appearances and origins of the com- 
rnoner rocks. The subsequent subject-matter follows 
chis order: formation of mountains and valleys, snow 
and glaciers, underground waters, relation of the sea to 
the land, the earth in its interior, volcanoes, earthquakes, 
coral and coral islands, fossils, physiognomy of the land- 
surface, common and useful metals and minerals, building 
stones, soils and fertilisers, and common rock-forming 
minerals. It will be seen from this outline that the book 
is comprehensive enough to meet the needs of the 
average student; its form is also popular enough to 
attract a large number of lay readers. 
The volume is most liberally illustrated, and the 
illustrations possess the immense advantage of being 
reproductions from photographs. There are sixty-four 
full-page plates, most of them containing two pictures, 
and all of them exhibiting striking objects or phenomena. 
We do not know of a better illustrated introductory text- 
book of geology than the one which Prof. Heilprin has 
given us. The book is more suitable for use in American 
colleges and high schools than in our own; but there 
ought to be a demand for it on this side of the Atlantic. 
The Climate of Bournemouth tn Relation to Disease, 
espectally Phthists. By A. Kinsey-Morgan, M.D., &c. 
Pp. 51. (Bristol: John Wright and Co., 1897.) 
THE impertant part which climate plays in the etiology 
and cure of lung diseases is well recognised. In this 
essay Dr. Kinsey-Morgan shows the advantages which 
Bournemouth offers to consumptive patients, or to persons 
suffering from any form of chest disease. He differs 
from writers on continental health-resorts and sanatoria, 
inasmuch as he points out how hygiene and medical 
influences must supplement climatic conditions, and 
insists that wholesome sanitary surroundings are more 
important points to be considered than particular thermal 
or mineral waters. 
LETTERS TO THE EDITOR. 
(The Editor does not hold himself responsible for opinions ex- 
pressed by hts correspondents. Neither can he undertake 
to return, or to correspond with the writers of, rejected 
manuscripts intended for this or any other part of NATURE. 
No notice ts taken of anonymous communications. | 
Carbon in Bright-Line Stars. 
In an article ‘‘On the Question of Carbon in Bright-line 
Stars,” in your issue of January 28, Prof. Lockyer makes the 
following statement in reference to our paper ‘“* On Wolf and 
Rayet’s Bright-line Stars in Cygnus.’’ 
“Asa result of their work, they make the following state- 
ment: ‘Our observations appear to us, however, to be con- 
clusive on the main subject of our inquiry, namely, that the 
bright blue band in the three Wolf-Rayet stars in Cygnus, and 
in DM 37° 3821, is not coincident with THE BLUE BAND 
OF THE BUNSEN FLAME.’ The capitals are mine. It 
will be seen how carefully Vogel, in the case of comets, and 
myself, in the case of stars, had pointed out that it was not a 
question of the Bunsen flame ! ” 
I am glad that the last words of the quotation from our paper 
were put in capitals, as they emphasise the assertions which we 
had to meet, namely, Prof. Lockyer’s assertions in an article in 
NATURE (vol. xlviii. p 344) :— 
“In the Bakerian Lecture for 1888, I gave a complete dis- 
NO. 1423, VOL. 55] 
cussion of the spectra of bright-lined stars, as far as the observa- 
tions went, and the conclusion arrived at was that they were 
nothing more than swarms of meteorites, a little more condensed 
than those we know as nebule. The main argument in favour 
of this conclusion was the presence of the bright fluting of 
carbon which extends from 468 to 474.” 
Now, this bright fluting of carbon is that known as the blue 
band of the Bunsen flame. The variations of the position of 
maximum of brightness which may take place within it, were 
fully discussed in our paper, and do not affect the range of 
wave-length. Even the anomalous band photographed from a 
vacuum tube at South Kensington gives little help, for it is 
scarcely necessary to repeat that in two stars the bright band 
lies outside this region; and in the other, though the maximum 
falls near the more refrangible limit of the blue carbon band, a 
large part of it falls outside the carbon band. 
But Prof. Lockyer himself puts beyond doubt that by his 
words, ‘‘the bright fluting of carbon,’ he did mean what we 
call ‘‘ the blue band of the Bunsen flame,” for he goes on to 
say (NATURE, 4c. ctt.) :— 
“*Direct comparisons of the spectrum of all three stars in 
Cygnus, with the flame of a spirit-lamp, have been made by 
Mr. Fowler, and SHOWED AN ABSOLUTE COINCIDENCE OF 
‘THE BRIGHT BAND IN THE STARS WITH THE BLUE BAND OF 
THE CARBON SEEN IN THE FLAME. It was found quite easy to 
get the narrow spectrum of the star superposed upon the 
broader spectrum of the flame, so that both could be observed 
simultaneously.” 
The capitals are mine. Now, bright bands having an absolute 
coincidence with the blue band of carbon in the flame, could be 
no other than the blue band scen in the Bunsen flame. This 
was the assertion which we had to meet ; an assertion stated to 
be supported by direct comparisons of the stars with a carbon 
flame. It was, therefore, necessary for us to make it clear that 
this assertion was incorrect ; and to say, in words which could 
not be mistaken, that “the bright blue band in the three stars 
is not coincident with the blue band of the Bunsen flame.” 
I am not aware that Prof. Lockyer has withdrawn the 
observations made at South Kensington. They are certainly 
remarkable, indeed unique, in the annals of spectroscopic 
research, for Mr. Fowler saw the blue band of his flame to have 
ABSOLUTE COINCIDENCE with three different star bands, which, 
all three, differ from each other in wave-length. 
If the blue band, differing in position in each star, were the 
blue carbon band, as Prof. Lockyer asserts it to be, we should * 
certainly expect to find in the spectra of the stars indications of 
the other bands of the carbon spectrum, especially of the bright 
green band and of the orange band. Now, there ave bright 
bands in these parts of the spectra of the stars: but we state in 
our paper, as the result of a very careful direct comparison of 
these bright places in the star-spectra with a carbon flame, that 
there is no connection whatever between the bright star bands 
and the carbon flutings. This important result has been fully 
confirmed by the recent measures of these bright star bands 
taken by Prof. Campbell. His measures of the bright places in 
the star spectra, whzch ave well seen upon the continuous 
spectrum, show with certainty that they have not their origin 
in carbon. Prof. Lockyer says that ‘* Prof. Campbell does 
not discuss the origins of the lines and bands which he has ~ 
measured.” 
Prof. Campbell's words are :— 
‘“* Tt is now a question of identifying the lines and bands with 
the lines of known elements, and of assigning to these stars their 
true place along with other types of celestial objects. A most 
perplexing question! The hydrogen lines, Ha, HB, Hy, H6, are 
present, but the other lines do not admit of certain identification. 
Prominent iron and other lines may coincide with a few of the 
star lines, and the line at 4480 suggests a magnesium origin ; 
but there are not enough points of identity with well-known 
artificial or stellar spectra to enable us to draw any safe con- 
clusions” (Astronomy and Astro-Physics, 1894, p- 472). 
As Prof. Vogel’s name is prominently brought forward in 
Prof. Lockyer’s article, it may be well to say that Prof. Vogel 
has nowhere identified the blue bands in the Wolf-Rayet stars, 
of which he was the first to determine the wave-lengths with 
any approach to precision, with the blue radiation of carbon. 
I should perhaps point out that, though Prof. Campbell does 
suggest magnesium, he is careful not to make any suggestion as 
to the presence of carbon. WILLIAM HUGGINS. 
Upper Tulse Hill, S.W., January 30. 
