serable house in a miserable street.
It was, I verily believe, one of the most wretched quarters I have ever
seen,--houses that must have been sordid and hideous enough when new,
that had gathered foulness with every year, and now seemed to lean and
totter to their fall. 'I live up there,' said Black, pointing to the
tiles, 'not in the front,--in the back. I am very quiet there. I won't
ask you to come in now, but perhaps some other day----'

"I caught him up at that, and told him I should be only too glad to
come and see him. He gave me an odd sort of glance, as if he was
wondering what on earth I or anybody else could care about him, and I
left him fumbling with his latch-key. I think you will say I did pretty
well, when I tell you that within a few weeks I had made myself an
intimate friend of Black's. I shall never forget the first time I went
to this room; I hope I shall never see such abject, squalid misery
again. The foul paper, from which all pattern or trace of a pattern had
long vanished, subdued and penetrated with the grime of the evil
street, was hanging in mouldering pennons from the wall. Only at the
end of the room was it possible to stand upright; and the sight of the
wretched bed and the odour of corruption that pervaded the place made
me turn faint and sick. Here I found him munching a piece of bread; he
seemed surprised to find that I had kept my promise, but he gave me his
chair, and sat on the bed while we talked. I used to go and see him
often, and we had long conversations together, but he never mentioned
Harlesden or his wife. I fancy that he supposed me ignorant of the
matter, or thought that if I had heard of it, I should never connect
the respectable Dr. Black of Harlesden with a poor garreteer in the
backwoods of London. He was a strange man, and as we sat together
smoking, I often wondered whether he were mad or sane, for I think the
wildest dreams of Paracelsus and the Rosicrucians would appear plain
and sober fact, compared with the theories I have heard him earnestly
advance in that grimy den of his. I once ventured to hint something of
the sort to him; I suggested that something he had said was in flat
contradiction to all science and all experience. 'No, Dyson,' he
answered, 'not all experience, for mine counts for something. I am no
dealer in unproved theories; what I say I have proved for myself, and
at a terrible cost. There is a region of knowledge of which you will
never know, whi