1895-96.] Mr Irvine and Dr Murray on Marine Muds. 
35 
On Chemical Changes in Marine Muds. By Robert Irvine 
and John Murray, LL.D. 
(Read January 20, 1896. ) 
On 16th December 1895 a paper written by Professor W. N. 
Hartley, F.R.S., Royal College of Science, Dublin, was read before 
this Society “ On the Cause and Nature of Chemical Changes 
occurring in Oceanic Deposits,” in which he criticised and took 
exception to certain conclusions we had arrived at, which formed 
the basis of a paper read by us in March 1892, and published 
in the Transactions of the Society, Yol. xxxvii., Part ii., No. 23, 
under the title “On the Chemical Changes which take place in 
the Composition of Sea-water associated with Blue Muds on the 
Floor of the Ocean.” 
At the time of writing his paper Professor Hartley had not seen 
ours, and was only in possession of the necessarily curtailed notice 
of it which appeared in Nature of January 24, 1895, from which 
he appears to have drawn inferences that a fuller knowledge would 
have altered. Practically, with the exception of one or two of 
our experimental results, Professor Hartley is in accord with us so 
far as the principal results are concerned. In taking exception to 
the formulae by which we endeavour to explain the decomposition 
of sulphates in sea-water in the presence of organic matter and 
ferric-hydrate, or ferruginous clay, he assumes the equations we 
use to mean the same as that which would occur in a black ash 
furnace under the influence of great heat. Our object in adopting 
the explanation of the reaction which appeared in our paper was to 
render it as simple as possible; and occurring as it does in mud 
saturated with water, we did not think it necessary to specially 
refer to the hydrous condition of the salts. 
The reduction of sulphates in mineral water by organic matter 
is so familiar to chemists that we need not refer further to it, 
except that it is acknowledged that most waters holding in solu- 
tion sulphides or sulphuretted hydrogen derive these from the 
deoxidation of the sulphates of the alkali or the alkaline earth 
present in the water. Of course, it was a reaction similar to this 
