PROCEEDINGS OF SOCIETIES. 115 



microscopical evidence at the trial, Dr. Bennet read some remarks from the Lord President' s 

 address to the jury, and took exceptions to some of them: — 



"The pursuer's witnesses told you that there was no trace of organic structure, no woody 

 fibre nor tissue, in short, no trace of vegetable matter in this substance, although occasionally 

 there might be the incidental presence of vegetable remains. The witnesses on the other side 

 told you, on the contrary, that in every part of it there were the most clear vestiges of vegetable 

 structure. I do not know when I have so many geologists and so many microseopists telling 

 nie that it is not coal, and so many on the other side telling me the opposite,— I say that I 

 do not know that I feel myself much the wiser, or further advanced in the inquiry. But if 

 you have, in addition, a great number of chemists, and speaking with equal authority and equal 

 contrariety, it is difficult to know what to make of the controversy. I do not know that I have 

 anything to say against the skill of the microseopists, or the skill of any of those gentlemen; 

 but one general remark may be made on the microscopic testimony, and it is that there are 

 those who sec a thing, and also those who do not see it— those who do see it cannot see it 

 unless it is there, and those who cannot see it do not see it at all. But very skilful person^ 

 looking for a thing and not seeing it, creates strong presumption that it is not there. But when 

 other persons do find it, it goes far to displace the notion that it is not there. But there is 

 another observation on the microscopic evidence that occurred to me. I do not know whether 

 I am under any misapprehension, but I think that three, certainly two, of those examined by 

 the defenders are botanists also; and I do not think that any of those examined for the pursuer, 

 two of them from Loudon, represented themselves as botanists. Now, the defender's witnesses 

 are accustomed to look for plants, and can understand them when they see them. The gentle- 

 men on the other side, again, looking for woody fibre or tissue, are not, as I understand, con- 

 versant or skilful in fossil plants. But finding such a difierence of opinion, and such opposite 

 conclusions arrived at by those persons, I do not know, unless you think that some gave their 

 reasons more satisfactorily than others — I say that I do not know that I feel my mind much 

 relieved from the difficulties of the case by listening to all that evidence." 



In allusion to the above remarks. Dr. Bennet stated that the differences in the results of the 

 observations of the witnesses on both sides of the case were more apparent than real, — the fact 

 being that both had seen the same thing, but had interpreted it in different ways, so that the 

 extraordinary circumstance of the defender's witnesses finding plants where the pursuer's could 

 see none was at once explained, without having recourse to the assumption, that the latter did 

 not know plants when he saw them. It was the globular bituminous bodies that gave rise to 

 the diff'erence of opinion; the defender's witnesses regarded them as vegetable cells, while those 

 for the pursuer did not believe in their vegetable origin. Without drawings it is impossible 

 for us to enter more fully into the details of facts relative to structure, etc., of which Dr. 

 Bennet's paper chiefly consisted; but this is not desirable, as the paper will, no doubt, appear 

 at full length in the "Eoyal Society's Transactions," or some other scientific publication. 

 Not so, however, with the discussion which followed the reading of the paper, — no sucih record 

 is likely to be made of it, and we therefore deem it important to occupy this vacant ground, 

 by reporting as fully as possible the opinions expressed by the various members who took part 

 in the debate. 



The Puesident having called for the opinions of members, Pkofessor Balfour rose, and 

 entered at great length upon the subject. While regretting that so much of the lloyal Society's 

 time should be occupied in the discussion of this questio vexata, he had hopes that the candid 

 spirit in which the subject had hitherto been discussed, would continue to mark the Society's 

 proceedings, and eventually lead to the discovery of the truth. He stated that it was impossible 

 to give an accurate definition of coal, which included many varieties of combustible material 

 formed from plants. Much depended on the nature of the plants, the pressure and heat to 

 which they had been subjected, the length of time which the deposit had taken to form coal, 

 and the degree of admixture of earthy matters. There was a gradual transition from anthracite 

 to parrot coal. Coals having an illuminating, gas-giving propertj', seemed to contain a peculiar 

 yellow matter, but this matter was very variable in its proportions, being much larger in Bog- 

 head gas-coal, and in Methil parrot, than in ordinary household coal; hence the value of the 

 two former in the manufacture of gas. The yellow matter appeared to be of vegetable origin, 

 and to have been formed from coal plants. It contained a considerable amount of carbon, and 

 had been deposited in circumscribed cavities of diflferent kinds. In considering the structure of 



