
De. 1, 1870] 
NATURE 
oF 

He thought that much of the denudation of the Wealden area 
might have taken place before the glacial period. The pre- 
sence of Tertiary pebbles in the Wealden area might readily be 
accounted for by their presence at the edge of the escarpment. 
Mr. Searles V. Wood, jun,, in reply, justified himself for having 
limited his observations to the northern part of the Weald, as it 
was there only that it could be brought into juxtaposition with 
the glacial beds. He maintained that, under certain circum- 
stances, no beaches or marine beds were formed at the base of 
sea-cliffs. He pointed out that in Post-glacial gravels large blocks 
of rock were frequently found, and protested against limiting all 
ice-transport to the glacial period. He could not recognise the 
Selsea beds, with 150 living species, some of southern character, 
and none extinct, as glacial. He did not acknowledge the alleged 
softness of the Wealden rocks.—The Earl of Enniskillen sent 
for exhibition a fragment of Lias Limestone from Lyme Regis 
perforated by Pholades. 
Entomological Society, November 21.—Mr. Alfred R. 
Wallace, F.Z.S., &c., President, in the chair. Exhibitions of 
Lepidoptera were made by Mr. Bond ; of Coleoptera by Mr. Albert 
Miiller and Prof. Westwood ; and Mr. F. Smith exhibited Phora 
Jiorea, a Dipterous parasite in the nest of the wasp. The follow- 
ing paper was read :—‘‘ Descriptions of some new diurnal Lefi- 
doptera, chiefly Hesperiide,” by Mr. A. G. Butler. 
Ethnological Society, November 22.—Prof. Huxley, Presi- 
dent, in the chair. Mr. George Macleay was announced asa 
newmember. Mr. Edgar Layard made some remarks upona 
collection of stone implements which he has recently brought 
from the Cape of Good Hope. Some polished celts from the 
Naga Hills, between Assam and Burmah, were exhibited, and 
Lieut. Barrow’s notes upon them were read.—A paper was then 
communicated by Dr. Bleek ‘‘On the Concord, the Origin of 
Pronouns, and the Formation of Genders or Classes of Nouns.” 
The author believes that the classes or genders in the sex- 
denoting languages originally depended, not upon the meaning of 
the nouns, but upon their representative particles, which, in these 
languages, were primiarily atthe end of the nouns. These gen- 
ders were, from an originally large number, gradually reduced, 
until in the Aryan languages they were mainly two—one with 
the representative element, U, which is called the mascu/ine class, 
and the other with the representative element, A TI, which is 
named the feminine class. The xewter appears to be a later 
development, into which, however, an original common plural 
gender, with the termination, A N I, may have been incorporated. 
To these endings the case-terminations were affixed, and through 

pressure of the latter the original marks of gender have frequently | 
been obscured. The concord was at first due to the presence of 
these representative elements of the nouns in their pronominal 
character. Mr. Hyde Clarke, in eulogising this paper, said 
that he had by independent investigation arrived at some of the 
results detailed by the author. The speaker insisted upon the 
necessity of extending our philological studies beyond the Indo- 
European languages. 
MANCHESTER 
Literary and Philosophical Society, November 15.— 
Mr. E. W. Binney, president, in the chair. “On the Tem- 
perature Equilibrium of an Enclosure containing a Body in 
Visible Motion,” by Prof. Balfour Stewart, LL.D., F.R.S. 
It has been established that in an enclosure containing bodies 
which are all at the same temperature, and at rest, the same 
amount of heat enters any surface forming part of the walls 
of the enclosure as leaves it in the same time, so that the body, 
of which this is the surface, neither gains nor loses heat. It is 
also known that if we take, not the outer surface of such a body, 
but any plane passing through its substance, say for instance one. 
parallel to its outer surface, then, as much heat passes across 
this plane going into the body, as passes across it going out of 
the body in the opposite direction ; and further, this equilibrium 
of heat is known to hold separately for every one of the indi- 
vidual rays of which the whole heterogeneous radiation is com- 
posed. The effect of the motion of a body in altering the wave- 
length of the radiated light is also well known. In consequence 
of this, if a cosmical mass, such as a star or nebula, should be 
formed of incandescent hydrogen, and beat the same time rapidly 
approaching the earth, the hght which strikes the earth will not 
be the double line D, but a line more refrangible than it, and 
therefore this light will be able to pass through a mass of ignited 
sedium vapour at the earth’s surface without suffering absorption, 
while, however, the light emanating from the sodium vapvur 

will still be the double line D. In such a case, even if the star 
and the terrestrial sodium vapour should both be of the same 
temperature, yet the light radiated by the latter will not be the 
same in quality as that absorbed. This instance would appear to 
show that the equilibrivm which holds in an enclosure of uniform 
temperature when all the substances are at rest does not hold when 
some of these are in visible motion, and that if in that en- 
closure there be a body moving towards or from the sur- 
face of the enclosure, the heat which enters the surface from 
the moving body will not be the same as that which the sur- 
face gives out. Suppose for instance that the walls of the en- 
closure are made of glass, and that the temperature of the 
| whole enclosure including that of the moving body is 0° C., then, 
were the whole at rest, the heat which strikes the glass surface 
will all be absorbed at a very short distance below the surface, 
and in like manner the heat radiated by the glass will all ema- 
nate from a short distance below the surface. But let us now 
suppose, to take an extreme case, that the moving body is ap- 
proaching one of the glass surfaces so rapidly that the heat 
which it emits has been so much increased in refrangibility as te 
enter the boundary of the visible spectrum. Then, while the 
heat radiated by the glass will still continue to proceed from a 
very short distance beneath the surface, the heat absorbed by 
the glass from the moving body will be able to penetrate toa very 
considerable depth beneath the surface of the glass. The outer 
layer of glass will thus lose, while the inner layer will gain 
heat. Now, it is possible to conceive an enclosure with a fixed 
diaphragm, and containing a revolving body, so arranged that 
the heat which leaves it in the direction of a certain part of the 
enclosing surface, shall always be given out by that part of the 
revolying body which is moving towards the surface ; while, on 
the other hand, the heat given out by the revolving body to 
another surface, shall be given out when the revolving body is 
moving from that surface. There will thus be a want of temper- 
ature equilibrium among the various layers, those near the sur- 
face being somewhat different in temperature from those beneath. 
But when we have a temperature difference of this kind, have we 
not acquired the power of converting heat into work? It would 
thus appear at first sight that the mere presence of a moving 
body has given us the power of obtaining work from an en- 
closure all of whose particles were originally at the same tem- 
perature. This appears however to be opposed to the theory 
of the dissipation of energy, and in consequence we are induced 
to think there must be some error in the assumption. Now, does 
not the unwarranted part of the hypothesis consist in our sup- 
posing that the revolving system can continue to reyolye without 
losing part of its visible motion? When two moving bodies ap- 
proach or recede from each other, is it not possible that each 
loses a small part of its visible energy, while at the same time 
there is a surface disturbance produced in both? It might be 
said that, believing in a medium pervading all space, we were 
prepared for a stoppage of motion of this nature, and that there 
is therefore nothing gained by the supposition which has been 
made ; but it might be replied that by looking at the problem in the 
above light, we appear to connect this stoppage of motion with 
other facts, besides being made aware of a source of surface dis- 
turbance when cosmical bodies approach or recede from each 
other.—Postscript added 19th November.—If we imagine a stop- 
page of the motion of cosmical bodies of the nature above de- 
scribed, then if the two approaching bodies be exactly equal 
and similar, either extremity of the medium between them will 
be similarly affected by the motion derived from the approach- 
ing bodies ; but if these bodies are unequal, the two extremities 
of the medium will be dissimilarly affected. 
Microscopical and Natural History Section, October 10.—Mr. 
Joseph Baxendell, President of the Section, in the chair. Mr. 
Joseph Sidebotham read the following paper :—‘‘ On the Varia- 
tions of Abraxas grossulariata.” The variations in animals and 
piants are of great interest, and each contribution to the store of 
facts accumulated relative to these variations, their causes and 
limits, is of value in determining the identity and limits of 
species, in whatever way we interpret the word sfecies. Abraxas 
grossulariata is probably one of the most variable insects we 
possess in this country in colour and markings, and it would be 
quite pardonable in any one not well acquainted with it, were he 
to split it up into four or five species ; but although it varies in 
colour and markings in such a great degree, all these varicties 
are joined together by gradual steps, and yet no step is found to 
join it to the next species on our list, dévaxas u/mata. The 
larvee of this species will feed upon the leaves of most trees and 
