“From a drop of water,” said the writer, “a logician could infer the possibility

of an Atlantic or a Niagara without having seen or heard of one or the other. So

all life is a great chain, the nature of which is known whenever we are shown a

single link of it. Like all other arts, the Science of Deduction and Analysis is

one which can only be acquired by long and patient study nor, is life long

enough to allow any mortal to attain the highest possible perfection in it.

Before turning to those moral and mental aspects of the matter which present the

greatest difficulties, let the enquirer begin by mastering more elementary

problems. Let him, on meeting a fellow-mortal, learn at a glance to distinguish

the history of the man, and the trade or profession to which he belongs. Puerile

as such an exercise may seem, it sharpens the faculties of observation, and

teaches one where to look and what to look for. By a man’s finger nails, by his

coat-sleeve, by his boot, by his trouser knees, by the callosities of his

forefinger and thumb, by his expression, by his shirt cuffs—by each of these

things a man’s calling is plainly revealed. That all united should fail to

enlighten the competent enquirer in any case is almost inconceivable.”

 

“What ineffable twaddle!” I cried, slapping the magazine down on the table, “I

never read such rubbish in my life.”

 

“What is it?” asked Sherlock Holmes.

 

“Why, this article,” I said, pointing at it with my egg spoon as I sat down to

my breakfast. “I see that you have read it since you have marked it. I don’t

deny that it is smartly written. It irritates me though. It is evidently the