414 
of nitrogen and carbon monoxide. The density-curve 
of the metal used and the expansion-coefficient of 
graphite are, of course, factors in the calculation of 
the results. One of the most interesting of these is 
that as: the temperature (575°) at which a-quartz 
passes into B-quartz is approached, a striking increase 
occurs in the rate of expansion. 
THE area of German East Africa to the south-east 
of the Victoria Nyanza and south of the frontier of 
British East Africa was explored in 1906-7 by Prof. 
Fritz Jaeger, Professor of Colonial Geography in 
Berlin, and his report on the Riesenkrater Highlands 
includes a detailed account of the interesting area 
which he investigated. It has been issued in the 
Mitteilungen aus den Deutschen Schutzgebieten, 
Erganzungsheft, No. 8 (1913, 4to, 213 pp., 12 pl., 3 
maps). The most interesting general problem in 
the area is the course across it of the Great Rift 
Valley of East Africa. The western wall of this 
valley continues southward, forming the western 
scarps above lakes Magadi, Manyara, and Balangda; 
but the eastern wall disappears in a wide volcanic 
belt which extends westward from the extinct vol- 
canoes of Kilima Njaro, and Meru. In the same 
district a series of faults branches off from the western 
wall of the Great Rift Valley and trends south- 
westward; these faults give rise to a series of rift 
valleys of which the largest includes the plains of 
Wembere and Lake Njarasa; a smaller one, Prof. 
Jaeger has called the MHohenlohe-Graben. These 
valleys may be really off-branches, and the main 
valley probably continues southward; its eastern 
wall may be represented by some faults, with a throw 
of more than 600 ft., which lie along the southern 
extension of the eastern side of Lake Manyara. The 
memoir includes a detailed account of the volcanic 
_ highlands to the north and west of Lake Manyara, 
which Prof. Jaeger has called the Riesenkrater 
Hochland. 
R. E. LieseGANG’s suggestions and experiments as 
to the osmotic deposition of concentric coats in 
chemical and mineral aggregates have received con- 
siderable attention among geologists, and notably 
from Mr. G. Abbott (Narure, vol. xcii., pp. 607 and 
687). Mr. Abbott has now published in the Pioneer 
(March 20 and 27, 1914) a further study of the discoid 
limestones which simulate organic characters in the 
concretionary beds of Permian age at Sunderland, 
and suggests that we must not ignore processes of 
mineral growth ‘even in the evolution of well-known 
organisms, such as corals.’’ We must not, he urges, 
“remain blind to what the alkaline earths can of 
themselves do in the formation of the skeletons of 
higher structures, in the roll of living things.” 
Mr. E. A. Martin, Hon. Curator of the Museum of 
the Borough of Croydon, South Norwood, writes to 
us on the same subject, pointing out that the 
secretion of carbonate of lime or silica by marine 
organisms may be ‘‘immensely assisted by the 
believes to have 
coralloid growths 
‘*Has this, too,” 
reason why some 
osmotic action which Mr. Abbott 
been the cause of the discoid and 
of the limestones of Fulwell Hill.’’ 
he asks, “‘anything to do with the 
NG: (2329, VOL @3 | 
NATURE 
| 
[JUNE 18, 1914 
shells are spiral, discoidal, bivalve, and so on?” Here 
the question appears to be one for the zoologist, 
who may be able to indicate a cause in the grouping 
of the soft parts of the animal, by which the external 
skeleton is controlled. 
A FIRST communication on the motion of the air in 
the lowest strata of the atmosphere, by Prof. G. Hell- 
mann, appeared in the Sitzungsberichte of the Prus- 
sian Academy of Sciences of April 2. As pointed out 
by the author, of all the meteorological elements deter- 
mined by instruments, none lacks comparability be- 
tween one place and another like wind velocity. This 
is due to some extent to instrumental defects, but more 
particularly to the extraordinary differences of expo- 
sure, especially height above the ground. Experiments 
are being carefully made by the Berlin Meteorological 
Institute at heights of 2, 16, and 32 metres, the results 
of which show an annual mean increase in velocity 
of 48 per cent. between 2 and 16 metres, but only 
14 per cent. between 16 and 32 metres; it is proposed 
to erect additional instruments at greater heights. 
Little variations in the increase of velocity with height 
were found to exist during the monthly periods, except 
at the lowest level, owing to friction with the surface. 
Some very interesting and unexpected results are 
referred to with respect to the completely opposite 
behaviour of the daily range of velocity in light and 
strong winds. The systematic study of the vertical 
wind components, such as those now in question, is 
of great importance at the present time. 
In the May number of the Proceedings of 
the American Academy, Dr. Louis Bell gives 
an account of an investigation of the types of 
abnormal colour vision he has commenced with the 
aid of the Rumford Fund. His spectroscopic 
apparatus allows him to classify his cases very 
rapidly. It depends on matching a synthetic yellow 
and a synthetic blue-green, which lie at the points of 
intersection of 
sensation curves for the normal eye, by a pure spec- 
trum which occupies the lower, while the synthetic 
colour occupies the upper half of the field of view. 
Of the twenty-six types of abnormality, Dr. Bell has 
already investigated the six possible types character- 
ised by deficiency or excess of sensitivity to one of 
the three fundamental colours, five of the twelve 
possible cases in which two of the fundamental sensa- 
tions are affected, and four of the eight possible cases 
in which three of the sensations are abnormal. He 
points out that the direction in which we must look 
for remedial measures is that of reducing the stronger 
sensation or sensations by means of coloured spec- 
tacles till the three are in the normal ratio. This can 
only be done in the deficiency cases at the expense 
of the general luminosity. 
PART. 3 2of vol. 11. 
the University of Sendai, 
important magnetic papers. The first, by Messrs. 
K. Honda and Y. Ogura, deals with the rela- 
tion between the changes with temperature of the 
electrical resistances and the magnetic  suscepti- 
bilities of iron, steel, and nickel. The materials were 
tested in the form of wires about a metre long and a 
of the Science Reports of 
Japan, contains two 
the red-green and the blue-green | 
ee ee ee 
