794 
NATURE 
[JUNE 9, 1923 : 

a more stable combination of nitrogen and hydrogen. 
The a band appears to be associated with a combina- 
tion of nitrogen and hydrogen of intermediate 
stability. The occurrence of the ultra-violet band 
alone in the solar spectrum ‘indicates that only the 
most stable combination of nitrogen and hydrogen 
can exist under the conditions that obtain in the 
reversing layer. 
Royal Microscopical Society, May 16.—E. J. 
Sheppard, vice-president, in the chair—W. M. 
Ames: Applications of the microscope in the manu- 
facture of rubber. This work falls into two divisions, 
examination of pigments and examination of micro- 
sections of rubber, both of which involve special 
methods. For work on pigments, particularly when 
investigating particle size, slides should be prepared 
by the method of Green so as to ensure uniform 
distribution of the pigment in one plane. The 
microscope enables relative particle sizes to be 
determined with certainty. Owing to the great 
resiliency of rubber, the preparation of sections 
sufficiently thin to be examined by transmitted 
light is difficult. Inorganic pigments if present can 
be identified, and their distribution studied. Certain 
organic materials such as fibre, reclaimed rubber, 
glue, and rubber substitute can also be identified. 
The behaviour of the sulphur formations in the 
rubber can be observed as the rubber perishes, and 
a comparison made between natural and artificial 
(heat) ageing. The variation, with temperature, of 
the solubility ofsulphur in vulcanised and unvulcanised 
rubber can also be observed. Wher rubber under 
strain is examined, vacua are found between the 
separate units of sulphur formations, and at the 
poles of crystalline pigments, but have not been 
detected in the case of gas-black or zinc oxide. 
Permanent internal deformation is visible in the 
rubber after retraction. 
Geological Society, May 16.—Prof. W. W. Watts, 
vice-president, in the chair.—W. B. R. King: The 
Upper Ordovician rocks of the South-Western Berwyn 
Hills. The district described lies in the south- 
eastern corner of the 1-inch Ordnance Survey Map, 
Sheet 136 (Bala). The area is one where the beds 
strike in a north-easterly and south-westerly direction, 
with dips nearly vertical. The black graptolitic 
shale-group is of shallow-water, probably lagoon, 
origin. The area appears to have been one of 
shallow water throughout Upper Ordovician times, 
and actually became land at the end of that period. 
The gap in the succession occasioned by this uplift 
was greatest in the south-east, near Welshpool ; 
while the areas on the north (Glyn Ceiriog) and west 
(Bala) remained under the sea. The shallowing of 
the water in these areas is, however, manifested by 
the deposition of either gritty beds or oolitic lime- 
stones. A new species of Calymene is described from 
the upper part of the Ashgillian, where it is taken as 
a local index-fossil.—W. J. Pugh: The geology of the 
district around Corris and Aberllefenni (Merioneth). 
The succession and structure of an area of about 25 
square miles, lying south-east of Cader Idris, are 
described. The area has been surveyed on the scale 
of 6 inches to the mile. The rocks are partly Lower 
Silurian and partly Upper Ordovician in age. The 
Valentian succession is similar to that described at 
Machynlleth (O. T. Jones and W. J. Pugh, Q.J.G.S. 
vol. Ixxi. (1915-16), p. 343), and the same classification 
is retained. It is considered to rest conformably upon 
the Bala series. The general strike, from south-west 
to north-east, is determined by the fact that the area 
lies on the south-eastern flank of the Harlech Dome; 
but the district is crossed by important folds transverse 
NO. 2797, VOL. IIT] 

to the normal strike. These structures have been 
correlated with those described farther south at 
Machynlleth. 
Aristotelian Society, May 28.—Prof. A. N. White- 
head, president, in the chair.—@, Delisle Burns: The — 
contact of minds. The word “‘ mind’”’ is taken to mean 
mental process or percipient event, and thus to refer 
to all such facts as thinking, feeling, and the sensation 
which accompanies or is part of thinking. It is 
generally admitted that mental processes are grouped 
so that they ‘“ belong to ”’ distinct persons or selves ; 
but there is also a connexion between these groups 
of mental processes in co-operation or communication 
or intercourse between persons. In communication 
“T” am aware that “you”’ are thinking, that is 
to say, I am aware that you are or have a mind ; 
or it may be said that I am aware that an “ other ’’ 
mind exists. The problem to be considered, then, 
is how I come to know that an other mind exists. 
The traditional view is that ‘‘ 1’ come to know that ~ 
other minds exist by a process of inference, based 
upon a comparison of my “‘ body ” with other bodies. 
This traditional view has already been attacked b 
Lossky and others. It seems false, first, because it 
implies a very unlikely description of psychological 
development. Secondly, at any stage in life the 
differences between my own body and other bodies 
in my contemplation are so great that the likeness 
can scarcely be a valid logical ground for the belief 
that other minds exist. As an alternative to the 
traditional view, therefore, it is suggested that Prof. 
Alexander’s term ‘enjoyment’ may provide an 
explanation of the way in which “ other” minds 
come to be known. But enjoyment must then be 
taken not to imply any process peculiar to “my” 
thinking or feeling. That is to say, there must be 
enjoyment of co-operation or communication. As 
objects are given in contemplation, so other minds 
are given in another form of awareness. There is, 
then, direct contact of minds, not “ through ”’ bodies 
or across any bridge which is non-mental. This, 
however, does not mean that mind is not bodily ; 
since mental process is probably the name for a 
relation, the terms of which are bodily. We need 
not assume that mental process is explicable in terms 
of ‘body ”’ or that “‘ body” is explicable in terms 
of mental process: but the contact of minds occurs 
in one area of reality and the contact of bodies in 
another, and the two are inseparable, as the force 
called gravitation is inseparable from ‘‘ mass.” 
DUBLIN. 
Royal Irish Academy, May 14.—Prof. Sydney 
Young, president, in the chair.—J. J. Nolan and 
J. Enright: Experiments on large ions in air. The 
effects of such substances as sulphur dioxide and 
ammonia on the development of large ions were 
investigated. The effect of temperature on the large 
ions was, examined. The large ion is unaffected 
up to 100° C., but at that temperature begins to 
break up. The coefficient of recombination between 
large and small ions was determined. The conditions 
under which multiple charges on the large ion can 
occur were investigated. The large ion in the atmo- 
sphere has probably a single electronic charge. 
EDINBURGH. 
Royal Society, May 7.—Prof. F. O. Bower, president, 
in the chair.—Miss A. V. Douglas: The sizes of 
particles in certain pelagic deposits. Samples of 
sea bottom brought back by the Quest from the South 
Atlantic bottoms were examined for the distribution 
of sizes of particles. The estimation is made by 

