Zht popular Science 0tM)s 
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BOSTON JOURNAL OF CHEMISTRY. 
Volume XXV. 
BOSTON, DECEMBER, 1891. 
Number 12. 
CONTENTS. 
Fajiiliar Science.— Some^Recent Advances "'^^ 
In Solar Spectroscopy '. 175 
The Astronomical Significance of Stone- 
henge 176 
Locusts 176 
Modification of Our Climate 177 
Sulphur 178 
Scientific Brevities ' 179 
The Out-Door Wokld.— Official Bulletin . 179 
Additions to the List of Councillors . . . 179 
Does the Agassiz Association Educate? . 179 
Diamonds in Meteoric Iron 179 
Original Observations by Members of the 
A. A 180 
The A. A. at the World's Fair 180 
Reports from Chapters 180 
The Evening Primrose and Other Flowers 
of Halifax 181 
Chapter Addresses, New and Revised . . 181 
Personal Observations by Miss Mattie 
Wadsworth, Chapter 535 182 
Editorial.— The Barberry Bush and Its 
Visitors 183 
Folli-lore and Superstitions of Some Amer- 
ican Indians 184 
Paris Letter 185 
Meteorology for October, 1891 186 
Astronomical Phenomena for December, 
1891 186 
Weight of the Carat 187 
Questions and Answers 187 
Literary Notes 187 
Medicine and Pharmacy.— Monthly Sum- 
mary of Medical Progress 188 
Ether or Chloroform? 189 
A Few Corn Cures 189 
The Licorice Plant 190 
An Early Proof of the Value of Vaccina- 
tion 190 
Medical Miscellany 190 
Publishers' Column 190 
familiar i§Gienee. 
roriji^nal In Populab Science News.] 
SOME RECENT ADVANCES IN SOLAR SPEC- 
TROSCOPY. 
BY prof. c. a. young. 
Within the last three or four years our knowl- 
edge of the solar spectrum and of the phenomena 
which are studied by means of the spectroscopic 
observation of the sun has made substantial prog- 
ress : in the present article we propose to enumer- 
ate the principal advances, and to call attention 
to such as are specially interesting or important. 
Our limits permit only a passing reference to 
the recent work of the veteran Janssen, who 
though no longer physically fit for mountain 
climbing, had himself carried to the summit of 
Mt. Blanc by a force of porters in order to study 
the debated question whether the great oxygen 
lines in the red region of the solar spectrum might 
not be, partly at least, of solar origin, notwith- 
standing the undoubted fact that they are mainly 
telluric. His observations on the mountain, taken 
in connection with those he made upon the elec- 
tric light on tlie Eiffel tower as seen from Meudon, 
have settled the question in the negative. 
We must content ourselves also with little more 
than a mere mention of the great map of the solar 
spectrum published last year by the Nice observa- 
tory ; the work of Thollen, who however did not 
live to see it finished. It extends from the red to 
the green, and is on a larger scale and more full of 
detail than any other yet issued : it is specially 
valuable for the manner in which it brings out the 
distinction between the telluric lines, originating 
in the atmosphere of the earth, and tliose which 
are truly solar, but on the other baud its scale is 
purely arbitrary, and this greatly limits its util- 
ity. On the whole the new edition of Rowland's 
photographic m.ap, which now covers the whole 
of the spectrum except a small region at the ex- 
treme red end, is incomparably more satisfactory ; 
it represents the ordinary appearance of the spec- 
trum with the minutest accuracy, and l)cars an 
absolutely trustworthy scale of wave-lengths. Its 
only drawback is that when the sun is near the 
horizon it ceases to correspond to tlie appearance 
presented: the telluric lines become so numerous 
and intense as to transform entirely the whole as- 
pect of certain regions of the spectrum, and the 
observer then is driven to ThoUon's map as the 
only one of mucli use under the circumstances. A 
new map of the spectrum, also photographic, is 
announced for early issue by Mr. Higgs of Liver- 
pool, who has already produced plates exceeding 
in Ijeauty and clearness of definition even the best 
of Rowland's ; but his work has been done with a 
Rowland grating, so that our American physicist 
can still claim a generous share of the credit for 
its excellence. In fact, the same may be said 
with reference to every piece of spectroscopic 
work we shall have occasion to speak of. 
Duner, in Sweden, has recently repeated the in- 
vestigation of the sun's rotation as measured by 
the displacement of the lines of the spectrum at 
the eastern and western edges of the sun's disk. 
His results confirm those of previous observers, 
extend them to higher latitudes, and are far more 
precise. IncidentallJ' he confirms an old observa- 
tion of the writer's in regard to the structure of 
sun-spot spectra, finding them to be made up of 
fine, closely packed, dark lines, and not produced 
by a mere continuous absorption. This fact is of 
importance in its bearings upon the theory of tlie 
spots, but for some reason has remained without 
verification until now. 
The most important piece of recent work in the 
line of solar spectroscopy is unquestionably Row- 
land's comparison of the solar spectrum with the 
spectra of the various chemical elements. It is, of 
course, to some extent only a repetition of work 
already done by others, but the new investigation 
is so much more thorough, and made with instru- 
ments of so much greater power that its results 
are incomparably more trustwortliy. The work is 
not yet entirely finished, but it has already 
greatly extended our knowledge, both by increas- 
ing the number of the elements recognized as 
present in the sun, and also in increasing the 
number of the lines identified as belonging to the 
spectra of the elements previously known. A 
large majority of the lines of the solar spectrum 
are now thus identified, and no less thau thivty- 
six of the terrestrial elements are recognized with 
certainty in the sun, while eight remain doubtful, 
and fifteen fail to give any evidence of their pres- 
ence after the most careful search ; ten remained 
to be tried at the time when the preliminary re- 
sults were published last spring. Of the sixteen 
elements added by this investigation to our for- 
mer list, the most important are carbon, silicon, 
silver and zinc : the detection in the sun of the 
newly discovered and rare metal germanium is 
also interesting; gallium as yet remains in the list 
of the untried. The most conspicuous of the 
•'absentees" are nitrogen, sulphur, phosphorus, 
mercurj', antimony and bismuth, while among 
those not yet examined are oxygen, bromine, 
chlorine, iodine and fluorine. 
Hardly less interesting is the recent work of 
Hale of Chicago and Deslandres of Paris upon the 
ultra-violet spectrum of the chromosphere and 
prominences as studied by means of photography. 
It has long been known that the two wide, dark 
bands known as H and K at the violet end of the 
solar spectrum are "reversed" in the spectrum of 
the cliromosphere and in the neighborhood of sun- 
spots in the same manner as the hydrogen lines ; 
indeed, this fact, in connection with some other 
circumstances, led some to suppose that these 
bands are really due to hydrogen, and not to cal- 
cium, as generally admitted. It now turns out 
that their observation by photography is as easy 
as their visual observation is difficult, and that in 
the spectrum of the chromosphere and promi- 
nences tliey appear as bright lines exceedingly 
thin and well-defined ; in striliing contrast with 
their width and haziness as dark lines in the spec- 
trum of the photosphere. Moreover, H is accom- 
panied by a companion line just below it, and well 
within the dark shade. Tliis line, which has been 
often observed visually, proves to be invariably 
present in the pliotographs ; and the same is true 
of another line above K (just at the extreme limit 
of vision) which had also been occasionally ob- 
served before. The photographs also bring out a 
number of other lines (four at least), quite be- 
yond the limit of visibility; and these six lines 
have all been unmistak.ably identified as belonging 
to the remarkable series of ultra-violet hydrogen 
lines wliich are so irapressivelj' conspicuous as 
wide black bands in the spectra of the great white 
stars like Sirius and Vega, but are missing in the 
spectra of the sun and of the stars that resemble 
it, that is as dark lines. Probably they are really 
present, but are comparatively faint, and masked 
by the heavy lines of other metals that crowd 
that part of the solar spectrum ; at least tliis is 
the opinion of Rowland. But their detection as 
l)right lines is very interesting as removing a 
puzzling anomaly. 
The close coincidence of H with its hydrogen 
neighbor also, explains another fact which has 
caused a great deal of perplexity ; namely, that in 
the " Sirian " stars H is tremendously black and 
strong, and K, when visible at all, is very faint 
and thin; while on the other hand, in the spec- 
trum of the suu and of the stars that resemble the 
