an agent for the bringing forth into vivid existence its due portion
of the illuminating or luciferous element; which element he supposes
to be diffused throughout the boundless regions of space, and which in
that case must be perfectly exhaustless. Further, assuming this
luciferous element to be not equally diffused through space, we find a
reason why in some ages of the earth's history the heat should have
been greater than at others, why stars have been seen to vary in
brightness, and why there was that puzzle to geologists--a glacial
period. During that period, according to Mr Nasmyth, with whose words
I finish this part of my communication, 'an arctic climate spread from
the poles towards the equator, and left the record of such a condition
in glacial handwriting on the mountain walls of our elder mountain
ravines, of which there is such abundant and unquestionable evidence.'

Our Microscopical Society have made a discovery in an all but
invisible subject: they now state the _Volvox globator_ to be a
vegetable, and not, as has long been supposed, an animal, as its
cells, presumed to be ova, are produced in the same way as in certain
kinds of _algæ_. In the discussion excited by this announcement, it
came out that several other minute forms, classed by Ehrenberg among
living animalcules, are in reality vegetable; which, if true, shews
that a good deal of microscopical work will have to be done over
again. The Syro-Egyptian Society, too, have heard something relating
to the same subject--a paper on Ehrenberg's examination by the
microscope of the anciently deposited alluvium of the Nile, from which
it appears that 'microscopic animals' in countless numbers were the
cause of the remarkable fertility of the soil, and not vegetable or
unctuous matters. Talking of deposits reminds me of a little fact
which I must not forget to mention--the finding of a fossil reptile in
the 'Old Red' of your county of Moray is, barring the alarm, as much a