JANUARY 14, 1904] 
NATURE 
259 
ttribromide to unsaturated compounds containing the group 
—CH:CH—. Thus desoxybenzoin, C,H,.CH,.CO.C,H,, 
is reduced to stilbene, C,H,.CH:CH.C,H,, and diphenyl- 
pyrazolone to diphenylpyrazole. The method is also applic- 
able to some compounds containing the group —NH.CO—, 
and carbostyril is in part reduced by phosphorus tribromide 
to quinoline. 
Tue long sought synthesis of camphoric acid has been 
recently accomplished by Dr. Komppa, of Helsingfors 
(Finland), and is described in the Berichte of December 29, 
1903. Two years ago the author described the synthesis of 
apocamphoric acid, which differs from camphoric acid only 
jin the presence of a hydrogen atom in place of one of the 
methyl groups. The methyl group cannot be introduced 
directly into apocamphoric acid, but the diketo-apocamphoric 
ester can be methylated and yields a diketocamphoric acid 
which can be indirectly reduced to camphoric acid, 
CO.CH.CO.Me CO.CH.CO,Me CH, catoaiu 
| } 
CMe, — | CMe, oa Cull: 
| | 
CO.CH.CO,Me  CO.CMe.CO,Me  CH,.CMe.CO,Me 
The synthetical acid is optically inactive, but proved to be 
identical with the known racemic form of camphoric acid. 
The synthesis includes also the preparation of camphor from 
its elements, since the conversion of camphoric acid into 
camphor was accomplished some years ago by Haller. 
Although the correctness of Bredt’s formula for camphor 
has been fully established by the synthesis of several of its 
oxidation products, the synthesis of the ketone itself has for 
some years been one of the most attractive problems in 
organic chemistry, and its solution completes a not un- 
important chapter in the history of chemical progress. 
Tue additions to the Zoological Society’s Gardens during 
the past week include a Raven (Corvus corax), British, 
presented by Mr. George Ogilvie; a Mongoose Lemur 
(Lemur mongoz) from Madagascar, two Sulphury Tyrants 
(Pitangus sulphuratus) from South America, deposited; a 
Llama (Lama peruana), born in the Gardens. 
OUR ASTRONOMICAL COLUMN. 
DISTRIBUTION OF THE Stars.—No. 5, vol. xlviii., of the 
Harvard College Observatory Annals contains a discussion 
of the distribution of the stars throughout the whole sky. 
A special point of the discussion was to determine the re- 
lative numbers of the stars situated in the Milky Way and 
those outside its limits. The number of stars in the galaxy 
was determined from the charts given in Heis’s atlas and 
the Uranometria Argentina; those without were determined 
from the Harvard Durchmusterungs. Twenty-three tables 
included in the paper set out the various results in detail, 
but the following are among the chief facts determined. 
The number of stars in a given area of the Milky Way 
is about twice as great as in an equal area of any other 
region, and this ratio does not increase for faint stars down 
to the twelfth magnitude; the proportion of stars of any 
given magnitude is the same in the Milky Way as in the 
other regions. The Milky Way covers about one-third of 
the sky, and contains about half of the stars. There is no 
evidence of any limit to the faintness of the stars, although 
the proportionate increase becomes less for each successive 
magnitude. There are about 10,000 stars of magnitude 6-6 
or brighter, 100,000 of magnitude 8-7, 1,000,000 of magni- 
tude Ibo, and 2,000,000 of magnitude 11-9. Although un- 
certain, it is suggested that there are about eighteen 
millions of stars visible in a telescope of 15 inches aperture, 
t.e. down to about the fifteenth magnitude. 
The distribution of various spectral types has also been 
considered, and the most striking fact is the preponderance | 
of stars of class ‘‘A” and ‘‘K” (Harvard), which in a 
NO. 1785, VOL. 69} 
~fact, about 14-5 inches below the average for forty years. 
general classification may be taken as typical spectra, the 
others being simply modifications of these. Many other 
extremely interesting facts have been elicited during the 
discussion, but they are too numerous to mention here. 
Report OF THE Winpsor, N.S.W., Oxsservatory.—Mr. 
Tebbutt’s report of the work performed at this observatory 
(Windsor, N.S.W.) during 1902 deals chiefly with meridian 
observations for the determination of local time and star 
places. Most of the extra-meridian work mentioned has 
already been published in the Astronomische Nachrichten, 
and includes observations of minor planets (for positions) 
and Perrine’s comet (1902 b). The reduced measures of 
fifty-four of the double-stars given in Inne’s ‘* Reference 
Catalogue,’’ involving 1757 settings for position angle and 
1503 for distance, have been communicated to the Royal 
Astronomical Society. The local meteorological results, 
given in the report, include monthly returns of temperature 
and rainfall observations, and show that the number of 
inches, recorded by a rain-gauge placed about 7 feet above 
the ground, is less than for any year since 1863, being, in 
A 
number of comparisons of the temperatures recorded by two 
thermometers, one in a Greenwich the other in a Stevenson 
screen, showed that an excess amounting to between one 
and two degrees was registered by the former. 
A vRENCH-CHINESE CaLenpar.—The “‘ Calendrier Annu- 
aire’’ for 1904, compiled at the Li-Ka-Wei Observatory, 
and published at the price of one dollar by the Catholic 
Mission at Shanghai, is an interesting calendar containing 
many astronomical, meteorological and physical tables. 
The calendar is printed in French, but all proper names 
and technical terms are also given in Chinese characters 
and words. Among the more important matters dealt with 
there occur a lucid explanation of the Chinese calendar, 
many astronomical tables and explanatory notes, tables for 
the conversion of Chinese and Japanese standards into 
European equivalents, facts regarding the population, area 
and political relations of China, and a number of tables and 
curves relating to the meteorology of the Chinese Empire. 
A Bricut BoLipe.—A remarkable bolide was observed by 
Mr. W. E. Rolston at Fulham at about 8h. 27m. p.m. on 
January g. It appeared at a point situated at about 
a=102°, 6=+18°, and slowly travelled towards the con- 
stellation Cancer, leaving a bright, scintillating, reddish 
trail. When near to the point a=112°, 5=+18° (approx.) 
the head slowly swelled out into a bulbous shape having a 
yellowish-red hue, became considerably brighter than 
Jupiter, and then suddenly disappeared. The duration of 
the complete phenomenon was about five or six seconds. 
THE PHYSICAL LABORATORY AT LEYDEN. 
AN account of this laboratory, published in Nature of 
August 13, 1896 (vol. liv. p. 345), dealt with the 
inception of the cryogenic department in 1883, and traced 
its development up to date. It is the purpose of this note 
to continue the account to the present time, both as regards 
the more important changes and improvements in the 
cryogenic department itself, and also in the remaining 
divisions of the laboratory. 
As before, the communications continue to give an 
almost complete account of the results of the practical work 
carried out, together with certain more theoretical papers 
in direct connection with this. Since 1898, the Royal 
Academy of Amsterdam has published its Proceedings 
in English as well as in Dutch, so that the communications 
are now corrected reprints of the Proceedings. Some idea 
may be gathered of the increasing output of work when it 
is noted that in 1896 the current number of the communi- 
cations was twenty-three, while it has now risen to eighty- 
eight. 
This increasing productivity is mainly due to the much 
improved appliances, both for manipulation and measure- 
ment, which have been developed during the last ten years. 
Although the original system of three main cycles contain- 
ing methyl chloride, ethylene and oxygen has been retained, 
almost evéry part has been improved and enlarged, so that 
the ease and rapidity of working are much enhanced. In 
