345 
of Edinburgh, Session 1879-80. 
subject, further than he himself had examined into it, after his 
own thoroughgoing manner, and to the satisfaction of the special 
ideal aspirations of his own soul. And herein was the most 
individual trait of the man — the rare cast of mind which made 
him a most worthy member of the Koyal Society of Edinburgh ; yet 
caused his worldly success in life, to fall far below his intrinsic worth 
and high capacities. 
Gifted by nature with a sensitive soul, responsive to the love of 
abstract truth and appreciative of ideal beauty; ever inclined to 
be generous beyond his means, and quite incapable, amidst higher 
surroundings, of bestowing serious and concentrated attention on 
petty affairs, he worked at his profession (photography) in a manner 
regardless of cost ; and not so much for profit, as for the sake of 
the scientific interest he involuntarily felt in overcoming diffi- 
culties in the practice of the art. That he did, from such motives, 
procure the most marvellous lenses and the most elaborate apparatus ; 
that he tried, with patient and often long-protracted and expensive 
experiments, every new method in photography, was to his honour as 
a lover of science ; but was not to his advantage as a man of very 
limited means, whose income mainly depended on daily studio work 
of a more certain kind. And, more untowardly still for his success 
in securing an adequate income, this taste for perfection and power 
in all the objective of his art, was accompanied by a curious inner 
subjective state of mind, — by a kind of inward psychical craving, 
perpetually urging him to desire, that his knowledge of whatever 
he touched, should be if possible more than perfect : persuading him 
too, that in order to know thoroughly any particular thing in nature, 
he should not only know and handle the thing itself, but that to be 
quite certain about it, he ought also to become similarly acquainted 
with everything else existent which, though outwardly excessively 
like, was not in reality the very thing itself ; and might in con- 
sequence, at some time or other, possibly deceive the unwary. Under 
the pure, but exacting, domination of which idea, carried as it was by 
him to an inordinately high degree, he appeared at last to think that, 
in the conduct of his scientific inquiries, his chief duty consisted 
rather in finding and proving a negative ; than in either establish- 
ing any positive result, or in securing opportunities for the most 
brilliant mercantile success. Had he been heir to a large fortune he 
