810 
THE VOYAGE OF H.M.S. CHALLENGER. 
“ Such are the objections which present themselves when it is proposed to pronounce 
upon the origin of particles which are regarded as cosmic, and of which a short description 
will be here given. Many of these doubts will be at once removed by a statement of the 
circumstances under which cosmic spherules are found in deep-sea deposits, and it will 
be found also that all the objections are disposed of by showing the association of metallic 
spherules with the most characteristic bodies of undoubted meteorites. 
“ In the first place, the considerable distance from land at which cosmic particles are 
found in greatest abundance in deep-sea deposits, eliminates at once objections which 
might be raised with respect to metallic particles found in the neighbourhood of inhabited 
countries. On the other hand, the form and character of the spherules of extra-terrestrial 
origin are essentially different from those collected near manufacturing centres. These 
magnetic spherules have never elongated necks or a cracked surface like those derived 
from furnaces with which they have been carefully compared. Neither are the magnetic 
spherules with a metallic centre comparable either in their form or structure to those 
particles of native iron which have been described in the eruptive rocks, especially in the 
basaltic rocks of the north of Ireland, of Iceland, &c. 
“ Having referred to the objections, what can now be said in support of the hypothesis 
that many of the magnetic particles from the bottom of the sea, which are especially abun- 
dant in those regions where the rate of accumulation of the deposit is exceedingly slow, 
are of cosmic origin ? If a magnet be plunged into an oceanic deposit, specially a red 
clay from the central parts of the Pacific, particles are extracted, some of which are 
magnetite from volcanic rocks, and to which vitreous matters are often attached ; others 
again are quite isolated, and differ in most of their properties from the former. The 
latter are generally round, measuring hardly 0‘2 mm., generally they are smaller, their 
surface is entirely covered with a brilliant black coating having all the properties of mag- 
netic oxide of iron, often there may be noticed upon them cup-like depressions clearly 
marked. If these spherules are broken down in an agate mortar, the brilliant black 
coating easily falls away and reveals white or grey metallic malleable nuclei, which may 
He beaten out by the pestle into thin lamellae. This metallic centre, when treated with 
an acidulated solution of sulphate of copper, immediately assumes a coppery coat, thus 
showing that it consists of native iron. But there are some malleable metallic nuclei 
extracted from the spherules which do not give this reaction. Chemical reaction 
shows that they contain cobalt and nickel ; very probably they constitute an alloy of 
iron and these two metals, such as is often found in meteorites, and the presence of which 
in large quantities hinders the production of the coppery coating on the iron. G. Rose has 
shown that this coating of black oxide of iron is found on the periphery of meteorites 
of native iron, and its presence is readily understood when their cosmic origin is 
admitted. Indeed, these meteoric particles of native iron in their transit through the 
air must undergo combustion, and, like small portions of iron from a smith’s anvil, 
