283 
which spores are present. Mr Carrurners, too, refers to 
them in the Geol. Mag. for 1865, page 433; but the first 
person who noticed the occurrence was the late Dr Firmine. 
Without wishing in the least to lessen the value of the 
investigations of some of the observers just referred to, it is 
necessary to understand on what basis they arrived at their 
conclusions. Professor Huxtry examined the coal microsco- 
pically, the sections having been cut by Mr KE. T. Newton, 
F.G.S. Sir Witxiram Dawson’s method was to examine the 
mineral charcoal by a process described on page 494 of his very 
able and valuable work on Acadian Geology. Specimens of 
coal were selected containing the tissue of only a single plant. 
These were boiled in strong nitric acid, and after the fumes 
had subsided the residue was washed and submitted to micro- 
scopic examination. Next, as to Mr Carrurners’s source of 
information, if I understand him correctly, there are in the 
British Museum a number of mud balls, said to have been 
derived from seams of coal. In these Mr Carruruers finds 
the remains of Carboniferous forest growth; and he assumes 
that therefore the seams of coal have been formed by like 
vegetation to that preserved in the mud balls. 
Let us now test the above sources of information. Professor 
Hovx.ey’s is, I contend, the only reliable one. If a transparent 
section of true coal can be obtained, nothing can disprove what 
it reveals. But even this method may lead one astray if the 
investigation be only partial. Sir Wizziam Dawson pointed 
this out to me, and suggested my preparing microscopic 
sections from various positions in a seam. I adopted this 
hint, and am much obliged for it: the results will be presently 
stated. Sir Wr11am Dawson’s method of treating selected 
specimens with nitric acid is, in my opinion, liable to mislead 
as to the general structure of the coal. First, I object 
to the principle of specially selecting a piece of coal for 
examination ; if we detect a fragment in a seam better 
preserved, with regard to structure, than the rest of the mass> 
the very fact should invoke caution, as there must be a cause 
_ for the preservation. It may be due to the fragment being a 
