"I have seen those devices of the Evil One," said Thornd.y.k.e, "in fact, I have one, which I bought at Charing Cross Station."

"Well, it seems that some months ago Mrs. Hornby, the wife of John Hornby, purchased one of these toys-"

"As a matter of fact," interrupted Reuben, "it was my cousin Walter who bought the thing and gave it to her."

"Well, that is not material," said Mr. Lawley (though I observed that Thornd.y.k.e made a note of the fact in his book); "at any rate, Mrs. Hornby became possessed of one of these appliances and proceeded to fill it with the thumb-prints of her friends, including her two nephews. Now it happened that the detective in charge of this case called yesterday at Mr. Hornby's house when the latter was absent from home, and took the opportunity of urging her to induce her husband to consent to have the thumb-prints of her nephews taken for the inspection of the experts at Scotland Yard. He pointed out that the procedure was really necessary, not only in the interests of justice but in the interests of the young men themselves, who were regarded with considerable suspicion by the police, which suspicion would be completely removed if it could be shown by actual comparison that the thumb-print could not have been made by either of them. Moreover, it seemed that both the young men had expressed their willingness to have the test applied, but had been forbidden by their uncle. Then Mrs. Hornby had a brilliant idea. She suddenly remembered the 'Thumbograph,' and thinking to set the question at rest once for all, fetched the little book and showed it to the detective. It contained the prints of both thumbs of Mr. Reuben (among others), and, as the detective had with him a photograph of the incriminating mark, the comparison was made then and there; and you may imagine Mrs. Hornby's horror and amazement when it was made clear that the print of her nephew Reuben's left thumb corresponded in every particular with the thumb-print that was found in the safe.

"At this juncture Mr. Hornby arrived on the scene and was, of course, overwhelmed with consternation at the turn events had taken. He would have liked to let the matter drop and make good the loss of the diamonds out of his own funds, but, as that would have amounted practically to compounding a felony, he had no choice but to prosecute. As a result, a warrant was issued for the arrest of Mr. Reuben, and was executed this morning, and my client was taken forthwith to Bow Street and charged with the robbery."

"Was any evidence taken?" asked Thornd.y.k.e.

"No. Only evidence of arrest. The prisoner is remanded for a week, bail having been accepted in two sureties of five hundred pounds each."

Thornd.y.k.e was silent for a s.p.a.ce after the conclusion of the narrative. Like me, he was evidently not agreeably impressed by the lawyer's manner, which seemed to take his client's guilt for granted, a position indeed not entirely without excuse having regard to the circ.u.mstances of the case.

"What have you advised your client to do?" Thornd.y.k.e asked presently.

"I have recommended him to plead guilty and throw himself on the clemency of the court as a first offender. You must see for yourself that there is no defence possible."

The young man flushed crimson, but made no remark.

"But let us be clear how we stand," said Thornd.y.k.e. "Are we defending an innocent man or are we endeavouring to obtain a light sentence for a man who admits that he is guilty?"

Mr. Lawley shrugged his shoulders.

"That question can be best answered by our client himself," said he.

Thornd.y.k.e directed an inquiring glance at Reuben Hornby, remarking-

"You are not called upon to incriminate yourself in any way, Mr. Hornby, but I must know what position you intend to adopt."

Here I again proposed to withdraw, but Reuben interrupted me.

"There is no need for you to go away, Dr. Jervis," he said. "My position is that I did not commit this robbery and that I know nothing whatever about it or about the thumb-print that was found in the safe. I do not, of course, expect you to believe me in the face of the overwhelming evidence against me, but I do, nevertheless, declare in the most solemn manner before G.o.d, that I am absolutely innocent of this crime and have no knowledge of it whatever."

"Then I take it that you did not plead 'guilty'?" said Thornd.y.k.e.

"Certainly not; and I never will," replied Reuben hotly.

"You would not be the first innocent man, by very many, who has entered that plea," remarked Mr. Lawley. "It is often the best policy, when the defence is hopelessly weak."

"It is a policy that will not be adopted by me," rejoined Reuben. "I may be, and probably shall be, convicted and sentenced, but I shall continue to maintain my innocence, whatever happens. Do you think," he added, turning to Thornd.y.k.e, "that you can undertake my defence on that a.s.sumption?"

"It is the only a.s.sumption on which I should agree to undertake the case," replied Thornd.y.k.e.

"And-if I may ask the question-" pursued Reuben anxiously, "do you find it possible to conceive that I may really be innocent?"

"Certainly I do," Thornd.y.k.e replied, on which I observed Mr. Lawley's eyebrows rise perceptibly. "I am a man of facts, not an advocate, and if I found it impossible to entertain the hypothesis of your innocence, I should not be willing to expend time and energy in searching for evidence to prove it. Nevertheless," he continued, seeing the light of hope break out on the face of the unfortunate young man, "I must impress upon you that the case presents enormous difficulties and that we must be prepared to find them insuperable in spite of all our efforts."

"I expect nothing but a conviction," replied Reuben in a calm and resolute voice, "and can face it like a man if only you do not take my guilt for granted, but give me a chance, no matter how small, of making a defence."

"Everything shall be done that I am capable of doing," said Thornd.y.k.e; "that I can promise you. The long odds against us are themselves a spur to endeavour, as far as I am concerned. And now, let me ask you, have you any cuts or scratches on your fingers?"

Reuben Hornby held out both his hands for my colleague's inspection, and I noticed that they were powerful and shapely, like the hands of a skilled craftsman, though faultlessly kept. Thornd.y.k.e set on the table a large condenser such as is used for microscopic work, and taking his client's hand, brought the bright spot of light to bear on each finger in succession, examining their tips and the parts around the nails with the aid of a pocket lens.

"A fine, capable hand, this," said he, regarding the member approvingly, as he finished his examination, "but I don't perceive any trace of a scar on either the right or left. Will you go over them, Jervis? The robbery took place a fortnight ago, so there has been time for a small cut or scratch to heal and disappear entirely. Still, the matter is worth noting."

He handed me the lens and I scrutinised every part of each hand without being able to detect the faintest trace of any recent wound.

"There is one other matter that must be attended to before you go," said Thornd.y.k.e, pressing the electric bell-push by his chair. "I will take one or two prints of the left thumb for my own information."

In response to the summons, Polton made his appearance from some lair unknown to me, but presumably the laboratory, and, having received his instructions, retired, and presently returned carrying a box, which he laid on the table. From this receptacle Thornd.y.k.e drew forth a bright copper plate mounted on a slab of hard wood, a small printer's roller, a tube of finger-print ink, and a number of cards with very white and rather glazed surfaces.

"Now, Mr. Hornby," said he, "your hands, I see, are beyond criticism as to cleanliness, but we will, nevertheless, give the thumb a final polish."

Accordingly he proceeded to brush the bulb of the thumb with a well-soaked badger-hair nail-brush, and, having rinsed it in water, dried it with a silk handkerchief, and gave it a final rub on a piece of chamois leather. The thumb having been thus prepared, he squeezed out a drop of the thick ink on to the copper plate and spread it out with the roller, testing the condition of the film from time to time by touching the plate with the tip of his finger and taking an impression on one of the cards.

When the ink had been rolled out to the requisite thinness, he took Reuben's hand and pressed the thumb lightly but firmly on to the inked plate; then, transferring the thumb to one of the cards, which he directed me to hold steady on the table, he repeated the pressure, when there was left on the card a beautifully sharp and clear impression of the bulb of the thumb, the tiny papillary ridges being shown with microscopic distinctness, and even the mouths of the sweat glands, which appeared as rows of little white dots on the black lines of the ridges. This manoeuvre was repeated a dozen times on two of the cards, each of which thus received six impressions. Thornd.y.k.e then took one or two rolled prints, i.e. prints produced by rolling the thumb first on the inked slab and then on the card, by which means a much larger portion of the surface of the thumb was displayed in a single print.

"And now," said Thornd.y.k.e, "that we may be furnished with all the necessary means of comparison, we will take an impression in blood."

The thumb was accordingly cleansed and dried afresh, when Thornd.y.k.e, having p.r.i.c.ked his own thumb with a needle, squeezed out a good-sized drop of blood on to a card.

"There," said he, with a smile, as he spread the drop out with the needle into a little shallow pool, "it is not every lawyer who is willing to shed his blood in the interests of his client."

He proceeded to make a dozen prints as before on two cards, writing a number with his pencil opposite each print as he made it.

"We are now," said he, as he finally cleansed his client's thumb, "furnished with the material for a preliminary investigation, and if you will now give me your address, Mr. Hornby, we may consider our business concluded for the present. I must apologise to you, Mr. Lawley, for having detained you so long with these experiments."

The lawyer had, in fact, been viewing the proceedings with hardly concealed impatience, and he now rose with evident relief that they were at an end.

"I have been highly interested," he said mendaciously, "though I confess I do not quite fathom your intentions. And, by the way, I should like to have a few words with you on another matter, if Mr. Reuben would not mind waiting for me in the square just a few minutes."

"Not at all," said Reuben, who was, I perceived, in no way deceived by the lawyer's pretence. "Don't hurry on my account; my time is my own-at present." He held out his hand to Thornd.y.k.e, who grasped it cordially.

"Good-bye, Mr. Hornby," said the latter. "Do not be unreasonably sanguine, but at the same time, do not lose heart. Keep your wits about you and let me know at once if anything occurs to you that may have a bearing on the case."

The young man then took his leave, and, as the door closed after him, Mr. Lawley turned towards Thornd.y.k.e.

"I thought I had better have a word with you alone," he said, "just to hear what line you propose to take up, for I confess that your att.i.tude has puzzled me completely."

"What line would you propose?" asked Thornd.y.k.e.

"Well," said the lawyer, with a shrug of his shoulders, "the position seems to be this: our young friend has stolen a parcel of diamonds and has been found out; at least, that is how the matter presents itself to me."

"That is not how it presents itself to me," said Thornd.y.k.e drily. "He may have taken the diamonds or he may not. I have no means of judging until I have sifted the evidence and acquired a few more facts. This I hope to do in the course of the next day or two, and I suggest that we postpone the consideration of our plan of campaign until I have seen what line of defence it is possible to adopt."

"As you will," replied the lawyer, taking up his hat, "but I am afraid you are encouraging the young rogue to entertain hopes that will only make his fall the harder-to say nothing of our own position. We don't want to make ourselves ridiculous in court, you know."