638 BRITISH ASSOCIATION FOR ADVANCEMENT OF SCIENCE. 
hearers may remember the graphic description by Her Majesty’s Envoy to 
Persia, the Hon. C. A. Murray, of the cloud of impalpable red-dust which 
darkened the air of Bagdad, and filled the city with a panic. The specimen 
he collected was examined by my successor, at the lloyal College of Sur- 
geons, Professor Quekett, and that experienced microscopist could detect 
only inorganic particles, such as fine quartz sand, without any trace of 
Diatomaceae or other organic matter. I)r. Lawson has obtained a similar 
result from the examination of the material of a shower of moist dust or 
mud which fell at Corfu, in March, 1857 ; it consisted for the most part of 
minute angular particles of a quartzose sand. Here, therefore, is a field of 
observation for the microscopist, which has doubtless most interesting re- 
sults as the reward of persevering research. 
The Earth and its Inhabitants. 
The advance of natural as of moral truth has been and is progressive : 
but it has pleased the Author of all truth to vary the fashion of the imparting 
of such parcels thereof as he has allotted, from time to time, for the behoof 
and guidance of mankind. Those who are privileged with the faculties of 
discovery are, therefere, to be regarded as pre-ordained instruments in 
making known the power of God, without a knowledge of which, as well as 
of Scripture, we are told that we shall err. Great and marvellous have 
been the manifestations of this power imparted to us of late times, not only 
in respect of the shape, motions, and solar relations of the earth, but also of 
its age and inhabitants. In regard to the period during which the globe 
allotted to man has revolved in its orbit, present evidence strains the mind 
to grasp such sum of past time with an effort like that by which it tries to 
realise the space dividing that orbit from the fixed stars and remoter nebulse. 
Yet, during all those eras that have passed since the Cambrian rocks were 
deposited which bear the impressed record of creative power, as it was then 
manifested, we know, through the interpreters of these “ writings on stone,” 
that the earth was vivified by the sun’s light and heat, was fertilized by re- 
freshing showers and washed by tidal waves. No stagnation has been per- 
mitted to air or ocean. The vast body of waters not only moved, as a 
whole, in orderly oscillations, regulated, as now, by sun and moon, but were 
rippled and agitated here and there successively by winds and storms. The 
atmosphere was healthily influenced by its horizontal currents, and by ever- 
varying clouds and vapours rising, condensing, dissolving, and falling in 
endless vertical circulation. With these conditions of life, we know that 
life itself has been enjoyed throughout the same countless thousands of 
years ; and that with life, from the beginning, there has been death . The 
earliest testimony of the living thing, whether shell, crust, or coral in the 
oldest fossiliferous rock, is at the same time proof that it died. It has fur- 
ther been given us to know, that not only tiie individual but the species 
perishes; that as death is balanced by generation, so extinction has been 
concomitant with creative power, which has continued to provide a succes- 
sion of species; and, furthermore, that as regards the varying forms of life 
which this planet has witnessed, there has been “ an advance and progress 
in the main.” Geology demonstrates that the creative force has not deserted 
this earth during any of her epochs of time ; and that in respect to no one 
class of animals has the manifestation of that force been limited to one 
epoch. Not a species of fish that now lives, but has come into being during 
a comparatively recent period ; the existing species were preceded by other 
species, and these again by others still more different from the present. No 
existing genus of fishes can be traced back beyond a moiety of known crea- 
tive time. Two entire orders (Cycloids and Ctenoids) have come into being, 
and have almost superseded two other orders (Ganoids and Placoids), since 
