APRIL 25, 1907 | 
well as chestnut offspring. (6) When crossed with a 
yellow-dun a white may yield grey-roan and white-dun 
offspring. (7) A black, crossed with a yellow-dun, may 
yield either yellow-dun or black offspring.—The geology 
of Ardrossan: Dr. J. D. Falconer. 
is given of the geological structure of the area in the 
immediate neighbourhood of Ardrossan, the suggestion 
being made that the Upper Old Red Sandstone and over- 
lying volcanic series were folded over an anticlinal axis 
striking north-west and south-east behind Ardrossan. The 
petrographical characters of the Carboniferous lavas and 
intrusive rocks are described in detail. Of the latter, the 
most important is the sill at Castle Craigs, more than 
half of which is composed of picrite. This rock passes 
upward into hornblende-dolerite along the whole length of 
the sill. The upper portion of the intrusion is fine grained 
and banded parallel with the upper surface, and is crossed 
by small pink felspathic veins. The sill affords an excel- 
lent example of the differentiation of one and the same 
magma into a lower basic and an upper felspathic portion. 
It is supposed to present considerable analogy to the 
banded peridotites and gabbros of Skye, and to differ from 
the Blackburn and Barnton picrites near Edinburgh, in 
which the differentiation took place entirely after intrusion. 
March 4.—Prof. Crum Brown, vice-president, in the 
chair.—Algebra after Hamilton, or multenions: Prof. 
Alexander M’Aulay. This is a system resembling in its 
generality the Ausdehnungslehre of Grassmann, but built 
on the lines of Hamilton’s quaternions. It differs from 
the Ausdehnungslehre in having only one method of multi- 
plication. The theory of the “‘linity,’’ analogous to the 
linear vector function in quaternions or to the matrix in 
algebra, is developed in considerable detail ; also the closely 
connected method of differentiation, which is based upon 
the properties of the generalised v.—Note on the change 
produced in the conductivity and density of lead wires 
by permanent stretching: J. A. Donaldson and R. 
Wilson. The experiments were carried out in the physical 
laboratory of Edinburgh University. The results were 
negative, there being within the errors of observation no 
appreciable change in either the electric conductivity or 
the density—The dynamical theory of seismometers: Dr. 
C. G., Knott. Some account was given of the recent 
important results, both theoretical and experimental, 
obtained by Prince Galitzin in his discussion of the theory 
of the horizontal pendulum, and a general discussion of 
earthquake records, now familiar to all students of 
seismology, led to the conclusion that, except for small, 
comparatively rapid vibrations of the ground, the amplitudes 
of the records could not be regarded as reproducing the 
motion of the ground even to a first approximation.— 
Temperature observations in the North Sea: Prof. D’Arcy 
W. Thompson. In this communication the author gave 
an account of methods and results which form a part of 
the second report of the North Sea Fisheries Investigation 
Committee. The material which formed the basis of the 
investigation was obtained partly from regular observ- 
ations made at lighthouses and on lightships, and partly 
from observations, furnished twice a day, by captains of 
passenger steamers. From these, by graphical interpola- 
tion, fair monthly means of water temperatures on the 
surface and ‘at various depths were obtained. Many 
interesting results were arrived at, especially with regard 
to the changes of temperature throughout the year and 
the range of annual change in different regions of the 
North Sea. See the Blue-book recently published by His 
Majesty’s Government. 
March 18.—Dr. R. H. Traquair, vice-president, in 
the chair.—The influence of temperature on the photo- 
electric discharge from platinum: Dr. W. Mansergh 
Varley and F. Unwin. The experiments were made in 
air, in carbon dioxide, and in hydrogen, at pressures vary- 
ing, in each gas, from atmospheric pressure to a pressure 
of 0-0035 mm. of mercury. In air and carbon dioxide at 
atmospheric pressure the photoelectric currents decreased 
with increase of temperature up to about 4co° C., after 
which they began to increase again. The maximum 
diminution in current was about 80 per cent. of the normal 
value. The behaviour of these two gases was identical. 
In hydrogen at this pressure, on the other hand, the 
currents steadily increased as the temperature was raised 
NO. 1956, VOL. 75] 
NALOURE 
A brief description | 
623 
from the crdinary temperature of the air. At the lowest 
pressure (0-0035 mm.) the photoelectric discharge in each 
gas was found to increase when the temperature was 
raised from that of the atmosphere to 60° C. Further 
increase of temperature up to 400° C. produced no change 
in the photoelectric current. When the temperature was 
reduced to the ordinary temperature of the air, the sensi- 
bility of the surface gradually diminished with time, fall- 
ing to half its value in about twenty-four hours. In all 
cases time was required for the sensibility to attain a 
steady value after any change in temperature.—Spiro- 
phyllum ferrugineum, a new genus and species of thread 
bacteria: D. Ellis. This flat, leaf-like, spirally wound 
organism was discovered by the author in iron-water 
ditches about a mile from Renfrew. The width varied 
from 1 » to 6 mw according to age, and the length might 
reach 200 w. The multiplication was by means of conidia, 
which germinated. Immediately after germination the 
organism had a slight motility, but this soon ceased. 
Before deposition of the iron the cell was semi-transparent. 
This new genus connects the iron bacteria, which at 
present are placed in the Chlamydobacteriacez, or thread- 
bacteria, with Spiromonas, a genus which must therefore 
be now included among the thread-bacteria.—The fune- 
tions of the Rolandic cortex in monkeys: Drs. W. A. Jolly 
and Sutherland Simpson. The object of the experiments, 
which were carried out in the physiological laboratory of 
Edinburgh University, was to delimit accurately the motor 
areas in the cortex cerebri of the monkey. The method 
employed was a new one. The cortex was stimulated by 
unipolar faradisation, and the areas were isolated by the 
use of vulcanite plates. The sharp edges of these plates 
were inserted into the cortex to a depth sufficient to divide 
the grey matter without penetrating the underlying white 
substance. It was shown that the movements of muscles 
resulting from stimulation of the ascending parietal con- 
volution were due to spread of current to the ascending 
frontal convolution. The motor centres in front of the 
fissure of Rolando and on the mesial aspect of the hemi- 
sphere were mapped out by application of the same isola- 
tion method.—Hydrates in aqueous solutions of electro- 
lytes: Rev. S. M. Johnstone. The paper gave results 
of extensive series of observations of the elevation of the 
boiling point and lowering of the freezing point in strong 
solutions, with determinations of conductivities at 0° C. 
and 99°-4 C. In most of the curves showing the relation 
between concentration and elevation per gram equivalent 
there was a minimum point, above which elevation per 
gram equivalent usually increased with concentration at 
a gradually diminishing rate. The hydration of the mole- 
cules and ions of the solutions examined was discussed 
on the admittedly doubtful assumption that the ionisation 
could be roughly determined from conductivity data. 
Freezing-point and boiling-point data were found to give 
very similar values of the extent of hydration, the de- 
liquescent salts giving the higher percentage hydrations. 
The number of molecules of water of hydration per mole- 
cule of solvent for a highly concentrated solution of a 
non-deliquescent salt was found in some cases to be much 
less than the number of molecules of water of crystallisa- 
tion. 
Paris. 
Academy of Sciences, April 15.—M. A. Chauveau in 
the chair.—Primitive tuberculosis of the lung and of the 
bronchial and mediastinal ganglions, communicated to 
young calves by the ingestion of tuberculous virus of bovine 
origin: A. Chauveau. A review of the author’s com- 
munications on the subject of tuberculous infection of the 
lungs through the alimentary canal, with especial refer- 
ence to the recent work of Calmette-——The application to 
pyridine of the method of direct hydrogenation by nickel : 
Paul Sabatier and A. Mailhe. At moderate tempera- 
tures (120° C. to 220° C.) pyridine is scarcely affected by 
this reaction, less than 1 per cent. being acted on. The 
amine formed is shown with certainty to differ from 
piperidine, the expected reduction product, and may 
possibly prove to be amylamine. If the reaction is allowed 
to proceed at higher temperatures, ammonia and pentane 
are produced in considerable quantities —Contribution to 
the pathogeny of pulmonary anthracosis: S. Arloing and 
E. Forgeot. A controversial paper directed against the 
