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Proceedings of the Royal Society 
and account for the great abundance of it in some such localities 
where we found it. 
Native Iron and Cosmic Dust . 
While examining the deposits during the cruise I frequently 
observed among the magnetic particles from our deep-sea clays 
small round black coloured particles which were attracted by the 
magnet, and I found it difficult to account for the origin of these. 
On our return home I entered into a more careful examination 
of the magnetic particles. By means of a magnet carefully 
covered with paper I extracted these particles from the deposits, 
from the pumice-stones, and from the manganese nodules of many 
regions. The great majority of these magnetic particles are 
magnetic iron ore and titaniferous iron, either in the form of 
crystals, or as line dust. In the clays, and in the manganese nodules 
from stations far from land and in deep water, there were again 
noticed many small, round spheres among the magnetic particles. 
On mentioning this to Professor G-eikie, he suggested that I 
should try the method employed by Professor Andrews of Belfast 
for detecting minute particles of native iron. 
This process consists in moistening the magnetic particles, which 
have been extracted by means of the magnet, with an acid solution 
of sulphate of copper, when copper is at once deposited on any 
native particles which may be present. In this way I have detected 
native iron in many of our deposits, in the powdered portions of 
manganese nodules, and in pumice-stones. 
Professor Andrews tells me that there can be little doubt that 
the particles on which copper is deposited are native iron, as he has 
found that it is not deposited on nickel, and the chances of cobalt 
being present are very slight. Professor Andrews warned me on 
the extreme precautions necessary in conducting these observations, 
that no iron from a hammer or other instrument should get at the 
specimen under observation. 
It is true that all specimens of our deposits have been obtained 
by means of dredges and iron gear, and some of these particles 
may be from this source. 
Many of the particles must have another origin. I have taken 
two of our manganese nodules, and washing them carefully, taking 
