444 
NATURE 
[Marcu 10, 1904 
ing to the same logarithmic law as in the case of the 
ionisation to one-half in 3-9 seconds. The rate of decay 
of the excited activity was also measured, and the half-value 
was found to be reached in 40 minutes. 
A REPRODUCTION, in the Chemical News of February 109, of 
Profs. Curie and Dewar’s paper on the examination of a 
sample of gas occluded in radium bromide contains a 
number of important details not referred to in the French 
paper recently summarised in these columns. Thus, in the 
experiments at the Royal Institution in which radium 
bromide was heated in a quartz tube, the condensable gases 
are stated to have contained water, bromine, and carbon 
dioxide in addition to the emanation, whilst the spectrum 
observed after freezing out the nitrogen was that of 
hydrogen, and not of nitrogen as stated in the Comptes 
yendus ; in such a tube, it is added, it would be impossible 
to find small amounts of helium by the spectroscope, seeing 
that a 10 per cent. helium-hydrogen mixture shows 
nothing but hydrogen. In reference to the subsequent 
appearance of the helium spectrum in the vacuous quartz 
tube, it is pointed out that ‘‘ until the full spectroscopic ex- 
amination by Deslandres is published no inference can be 
drawn as to whether or no the amount of helium has gone 
on increasing in the quartz tube (as it ought to do if it is 
a true product of the disintegration of radium), and no con- 
clusion drawn as to the presence of other gases and their 
origin, whether new or old.’’ 
An exceedingly interesting summary of the recent work 
of Profs. Elster and Geitel on the radio-activity of the air 
and the soil is contained in a recent number of the Geneva 
Archives des Sciences. In order to test whether the radio- 
activity of the air was inherent or induced from outside, a 
steel boiler of 23 cubic metres capacity was kept closed 
during six weeks, and an aluminium wire was then intro- 
duced and negatively charged to a potential of 2000 volts; 
no radio-activity was induced on the wire, and the air, 
isolated in this way from the rest of the atmosphere, was 
completely inactive. The radio-activity is attributed to an 
emanation produced by some radio-active substance in the 
soil which finds its way into the included air, and thence into 
the free atmosphere as well as into the water of mineral 
springs. An attempt was made to isolate the radio-active 
constituent of a specially active earth from the Italian Alps, 
and the results obtained were in accordance with the view 
that the soil contained a trace of radium; the hydrochloric 
acid extract yielded a barium sulphate precipitate about as 
active as potassium uranyl sulphate, and a platinum kathode 
immersed in the solution became permanently (?) radio- 
active. Further support of this view is found in the fact 
that the induced activity separated from the air decays at 
the same rate as that induced by radium salts. 
We have received the first part of the ‘ Abhandlungen zur 
Didaktik und Philosophie der Naturwissenschaft,’’ which 
are being issued as adjuncts to the Zeitschrift fiir den 
physikalischen und chemischen Unterricht. These are in- 
tended to be monographs in a more extended form on matters 
such as those considered in the Zeitschrift. The present 
number, by Herr E. Grimsehl, of Hamburg (who is one 
of the general editors), is on ‘‘ Die elektrische Glihlampe 
im Dienste des physikalischen Unterrichts,’’ and deals, so 
far as is possible in the sixty pages at disposal, with the 
numerous uses to which electric glow lamps can be put in 
physical demonstrations. Many of these uses are probably 
well known to most lecturers who have had experience in 
NO. 1793, VOL. 69 
demonstrating to large audiences, but the beginner will be 
able to pick up a great number of hints from the descrip- 
tions given. The apparatus described can all be obtained 
from the firm of A. Kriiss in Hamburg. 
Tur United States Weather Bureau has recently issued 
a memoir on the climatology of California, prepared under 
the direction of Prof. W. L. Moore by A. G. McAdie, pro- 
fessor of meteorology. The author points out that the 
climate of California is controlled by four great factors :— 
(1) the movements of the areas of high and low barometric 
pressure; (2) the prevailing drift of the atmosphere from 
west to east; (3) the proximity of the Pacific Ocean, with 
a mean annual temperature near the coast line of about 
55°; and (4) the exceedingly diversified topography of the 
country for a distance of 200 miles from the coast inland. 
To illustrate these leading features, long series of observ- 
ations at suitably chosen localities have been elaborately 
discussed in 260 large quarto pages, with 42 diagrams and 
charts, and furnish a very valuable contribution to meteor- 
ological knowledge. The remarkable pictures of fog 
billows obtained at the Observatory of Mount Tamalpais, 
and noticed in our columns some time ago, are reproduced 
in an interesting article on the fog of the district of San 
Francisco. 
WE have received a copy of the second part of the Psycho- 
logical Bulletin, which is devoted to the literary section of 
the Psychological Review. It includes the proceedings of 
the American Psychological and Philosophical Associations. 
Tue volume of the Proceedings of the Philadelphia 
Academy for the current year opens with the first part of 
a paper by Mr. H. Pilsbry on new Japanese molluscs, this 
instalment being devoted to gastropods. The number of 
species described is very large; unfortunately, one of the 
names—Conus dormitor—has long been preoccupied for 
the well-known shell from the Barton Eocene. 
In the Proceedings of the South African Philosophical 
Society, Mr. W. L. Distant describes a number of new 
South African Tingidide and other Heteroptera. In a 
previous paper the author enumerated twenty-six species, 
distributed in twelve genera as non-Palzarctic species of the 
African mainland; the present list raises the number of 
species to forty, and of genera to twenty-one. It may be 
considered a pity that the author uses the generic name of 
a common tree, Ulmus, to designate a new genus of insects. 
AccorpING to its report, the efforts of the Society for the 
Protection of Birds were mainly devoted during 1903 to 
securing more effectual protection for the breeding-places 
and eggs of our rarer birds, to the extension of the com- 
petitions in connection with ‘‘ Bird and Tree Day,’ and 
to further exposure of certain alleged frauds in regard to 
so-called artificial osprey plumes and the suppression of 
birds’ plumage in millinery. The ‘‘ watchers’ fund,” 
started in 1902, not having met with so much support as 
was expected, limited expenditure on the first item. It is 
suggested that the endeavour may be made to render both 
the sale and possession of skins and eggs of rare birds 
illegal, but this is surely far too drastic a measure to meet 
with public approval. Most or all of the so-called artificial 
“ ospreys ’’ were found to be real egret plumes. 
Aw excellent portrait of Prof. D. J. Cunningham appears 
in the report of the Royal Zoological Society of Ireland for 
the past year. His appointment to the chair of anatomy at 
Edinburgh has compelled Prof. Cunningham to retire from 
