“The bullet was virtually a hypodermic syringe; the poison in this cigar has been introduced, in the form of an alcoholic or ethereal solution, by a hypodermic syringe.  We shall thus be justified in assuming that the bullet and the cigar came from the same person; and, if this be so, we may say that X is a person of considerable knowledge, of great ingenuity and no mean skill as a mechanician—­as shown by the manufacture of the bullet.

“These are our principal facts—­to which we may add the surmise that he has recently purchased a second-hand Blickensderfer of the literary form or, at least, fitted with a literary typewheel.”

“I don’t quite see how you arrive at that,” I said, in some surprise.

“It is merely a guess, you know,” he replied, “though a probable one.  In the first place he is obviously unused to typing, as the numerous mistakes show; therefore he has not had the machine very long.  The type is that which is peculiar to the Blickensderfer, and, in one of the mistakes, an asterisk has been printed in place of a letter.  But the literary typewheel is the only one that has the asterisk.  As to the age of the machine, there are evident signs of wear, for some of the letters have lost their sharpness, and this is most evident in the case of those letters which are the most used—­the ‘e,’ you will notice, for instance, is much worn; and ‘e’ occurs more frequently than any other letter of the alphabet.  Hence the machine, if recently purchased, was bought second-hand.”

“But,” I objected, “it may not have been his own machine at all.”

“That is quite possible,” answered Thorndyke, “though, considering the secrecy that would be necessary, the probabilities are in favour of his having bought it.  But, in any case, we have here a means of identifying the machine, should we ever meet with it.”

He picked up the label and handed it to me, together with his pocket lens.

“Look closely at the ‘e’ that we have been discussing; it occurs five times; in ‘Thorndyke,’ in ‘Bench,’ in ‘Inner,’ and in ‘Temple.’  Now in each case you will notice a minute break in the loop, just at the summit.  That break corresponds to a tiny dent in the type—­caused, probably, by its striking some small, hard object.”

“I can make it out quite distinctly,” I said, “and it should be a most valuable point for identification.”

“It should be almost conclusive,” Thorndyke replied, “especially when joined to other facts that would be elicited by a search of his premises.  And now let us just recapitulate the facts which our friend X has placed at our disposal.

“First:  X is a person concerning whom I possess certain exclusive information.

“Second:  He has some knowledge of my personal habits.

“Third:  He is a man of some means and social position.

“Fourth:  He is a man of considerable knowledge, ingenuity and mechanical skill.