DECEMBER 6, 1906| 
glucosides susceptible of decomposition by specific enzymes 
with the production of the highly-poisonous prussic acid. 
In a communication to the Royal Academy of Belgium 
(Bulletin No. 8, p. 613) M. P. Fitschy adds another half- 
dozen common plants to the number of those already known 
to produce prussic acid in the early stages of their growth. 
Among the Ranunculacee are R. repens and R. arvensis, 
and among the grasses Gynerium argenteum, Melica 
altissima, M. nutans, M. uniflora, and M. ctliata. It re- 
mains to be ascertained whether the prussic acid is 
originally elaborated in each plant in the form of a definite 
glucoside, and whether a specific enzyme is responsible 
for its decomposition. 
A NEW edition of Mr. Sidney Lupton’s ‘* Numerical 
Tables and Constants in Elementary Science’’ has been 
published by Messrs. Macmillan and Co., Ltd. The pre- 
sent issue is substantially similar to the last edition, but 
a few values have been corrected, and an addendum of 
two pages contains important values and constants recently 
obtained. 
A SUPPLEMENT to the report of the Rugby School Natural 
History Society for the year 1905 has been published. It 
contains a paper by Mr. G. L. Keynes on a late Roman 
settlement near Somersham, Hunts, and is illustrated with 
photographs and drawings of the objects found during the 
excavation of the settlement. 
Messrs. Brapy aNp Martin, Ltp., of Newcastle-upon- 
Tyne, have issued the seventh edition of their well-arranged 
catalogue (pp. 700) of scientific apparatus. This enter- 
prising firm is prepared to supply instruments and material 
for the practical study of all branches of science, and 
teachers will do well to examine the volume when select- 
ing apparatus or accessories for lecture-room or laboratory. 
THE use of models for the teaching of solid geometry 
forms the subject of two articles by M. Charles Playoust 
in Cosmos for September 8 and 15, the object being to 
show how easily models can be constructed out of card- 
board or with strings by a teacher or student, in cases 
where the cost of a set of proper models would be 
prohibitive. 
An English version of Prof. H. Poincaré’s articles on 
“The Value of Science’’ is appearing month by month 
in the Popular Science Monthly. The November article 
deals with ‘‘ The Notion of Space.’’ A German translation 
of the same book by Prof. and Frau Weber, of Strassburg, 
has been published by Teubner, of Leipzig. 
OUR ASTRONOMICAL COLUMN. 
Discovery oF A Nova.—Circular No. 121 of the Harvard 
College Observatory contains an account of the discovery, 
by Miss Leavitt, of a new star in the constellation Vela. 
This object was discovered on a plate taken with the 1-inch 
Cooke lens on December 5, 1905, and also on fourteen 
plates taken between that date and June 29, 1906. Its 
position, for 1900, is 
R.A.=10h. 58m. 20s., dec. = —53° 50’-9. 
On a plate taken on July 12, 1905, showing stars down 
to magnitude 11-5, Nova Velorum is not to be found, nor 
did it appear on the 127 plates of this region taken between 
1889 and December, 1905, all of which have been examined 
and found to show stars down to the eleventh magnitude. 
So far as can be determined from the Harvard plates, the 
greatest magnitude attained by this Nova was 9-72, the 
magnitude on December 5, 1905, and January 26, 1906. 
There were considerable fluctuations of light during the 
NO. 1936, VOL 75| 
IN OMNI MOE SIE: 
137 
| period covered by the observations, and Prof. Pickering 
| thinks there is little doubt that the object observed is 
actually a Nova. 
CoMETS 1906g AND 1906h.—QObservations of these two 
comets are recorded in Nos. 4135-6 of the Astronomische 
Nachrichten. Observing at Arcetri, Prof. Abetti saw 
comet 1906g as a round, uniform nebulosity of 2’ diameter, 
in which neither nucleus nor any trace of a tail could 
be discerned. Prof. Ambronn, at Gottingen, found a 
feeble condensation, but no nucleus, on November 19. 
According to Prof. Nijland, the magnitude, as estimated 
from an opera-glass observation on November 19, was 7-7- 
A set of elements computed by Herr M. Ebell for comet 
1906h, and published in Circular No. 94 from the Kiel 
Centralstelle, shows that this body passed through peri- 
helion on September 15. The Circular also gives an 
ephemeris from November 26 to December 16, which shows 
that the comet’s brightness is decreasing. 
OBSERVATIONS OF Nova Sacittarit.—Since May 10, 1899, 
Prof. Barnard has observed Nova Sagittarii on many 
occasions with the 4o-inch refractor at Yerkes, and now 
publishes the results in No. 4136 of the Astronomische 
Nachrichten. This Nova was discovered from the Harvard 
photographs, of which one, taken on March 8, 1898, showed 
it to be of magnitude 4-7. Prof. Barnard’s observations gave 
the following magnitudes for the mean dates of the years 
named :—1899, mag. 11-0; 1903, mag. 13-8; 1906, mag. 
14-8. From these it appears that the Nova may fade 
entirely from view in the next few years. The published 
positions of this star seem rather discordant, so Prof. 
Barnard has investigated the matter, and gives data which 
will prevent the position of the Nova from being mistaken. 
The appearance of the Nova in the 4o-inch telescope is 
that of a very small nebula, or hazy star, about 1” in 
diameter. Extending the focus about one-quarter of an 
inch seemed to improve the definition, but still left the 
image of the Nova hazy, something like the abnormal stars 
in the cluster M13 Herculis. 
Two STARS WITH VARIABLE RapiAL VELOCITIES.—From 
spectrograms taken at the Potsdam Observatory, Prof. 
Hartmann has discovered that the two stars RZ Cassiopeiz 
(an Algol variable provisionally designated 77.1906 Cassio- 
peiz) and y Cassiopeiz have variable radial velocities. 
In the former case the spectrograms show a variation 
between + 33-1 km. (October 1, 1906) and —111-9 km. 
(October 4, 1906), the first value obtaining about one- 
quarter of the star’s period before, and the second about 
the same length of time after, the minimum. The measures 
of the spectrograms of y Cassiopeiz gave values between 
+3:1 km. (September 21, 1900) and —19-3 km. (September 
27, 1901). Owing to the hazy character of the lines in the 
spectrum of this star, the resulting velocities are somewhat 
uncertain (Astronomische Nachrichten, No. 4135). 
GrapuHitic IRON 1n A MeETEORITE.—In an extract (No. 
1497) from the Proceedings of the U.S. National Museum 
Mr. W. Tassin describes the physical and chemical proper- 
ties of a nodule of graphitic iron found in the Canyon 
Diablo meteorite. The mass was found on examination to 
be a septarian nodule, the septa consisting of native metals 
similar to the mass of iron. The interseptal portions 
consist of crystalline graphitic and amorphous carbon, 
mixed with a very fine granular or scaly froilite. There 
is also present a lustrous metallic substance differing 
from cohenite in that it is soft enough to leave a mark 
on white paper, is dark steel-grey in colour, and occurs 
in angular, foliated masses. Chemical analysis showed 
that this material contained iron (88-8 per cent.), nickel 
(4-0 per cent.), silicon (2-0 per cent.), carbon (4-3 per cent.), 
phosphorus (0-9 per cent.), and a trace of cobalt. 
New Varras_te Stars.—In No. 4126 of the Astronomische 
Nachrichten Prof. Max Wolf announces the discovery of 
thirty-one new variable stars in the region about 8 Cygni. 
The variability of these objects was discovered from plates 
taken with the Bruce telescope with exposures ranging 
from 150 to 220 minutes. A number of separate charts 
show the positions of these stars. 
