58 Structure of a pecaliar Combustible Mineral, 
1 made drawings of tlie outline and structure of two or three hundred 
ferns alone. 
Were you asked to assist some gentlemen using the microscope to 
represent the appearance of some sections of minerals ? — Yes. 
These are the drawings you made ? — Yes. 
Did you yourself look at various sections of the minerals besides those 
that yoa have represented? — I did, especially with regard to the Boghead 
mineral. I examined under the microscope eighteen different slices made 
from eight different specimens of the substance. 
Were these Dr. Kedfern's specimens ? — Yes. 
Did you discover vegetable structure in these ? — Unquestionably, in 
the whole of them. 
Did you examine some other minerals — some cannel coals that this 
gentleman had ? — I examined all those coals of which the names are 
appended to the drawings. There is the Methil, Lesmahagow, and 
Capeldrae coals. 
Now these are correct representations, to the best of your ability, of 
what they present ? — They are ; they might be more minutely finished, 
but they give, 1 hope, a fair representation of the structure. 
Did it appear to you, from your examination of these different things, 
that they were the general structure of the mass, or any incidental 
structure ? — I have no hesitation in saying that it was the general 
structure of every specimen, not incidental. I should consider it to be 
quite impossible it could be incidental. 
Do you consider that there is a material difference or a substantial 
identity between these different bodies, as represented in these different 
minerals ? — I do not. I examined the specimens of the three upper- 
most sketches, and the structure was so similar, that I considered them 
to be identical. There is a difference, but nothing amounting to any- 
thing essential in the structure. The Lesmahagow, Capeldrae, and 
Torbanehill are essentially the same. I may be allowed to add, that in 
each slice there is a difference in every part of that slice, so that you 
must be guided by the general view. 
From yoLir botanical knowledge, have you any doubt that these repre- 
sentations exhibit vegetable cells ?~1 have no more doubt of that than of 
my own existence at this moment. 
Will you explain what that paper is ? — [handing witness one of the 
drawings spoken to by Professor Balfour] — That drawing represents 
vegetable cells in an isolated state, scattered throughout the substance, and 
observable, I believe, in most coals — certainly in most coals tliat I have 
examined. It is difficult to say what they may be, but I have no doubt 
that they are vegetable cells, solitary cells. They may possibly be 
transverse segments of cells, but I would not venture to say anything 
more than that. I believe them to be vegetable cells. 
Found in this mineral ? — We have found these vegetable cells in the 
Boghead as well as in others. 
Will you explain what these two drawings represent ? — [handing witness 
two of the drawings spoken to by Professor Balfour] — The uppermost one 
represents cellular tissue in the Torbanehill mineral; and, upon the 
whole, I consider that as one of the most satisfactory specimens which I 
examined ; the cellular tissue is so unequivocally marked, and so regular, 
that it may be compared to that of a recent plant. It is exceedingly well 
defined. What I have represented in the drawing is not in the least 
exaggerated. No person accustomed to botanical sections would hesitate 
in believing that to be cellular tissue. The lower drawing repitsents a 
beautiful specimen, but whether that is general in the mineral I could not 
