substances so mysterious, subtle, and dangerous as to set the most delicate tests and powerful lenses at naught, while they carry death most horrible in their train."
He could scarcely have chosen his opening words with more effect.
"Chief among them," he proceeded, "are those from nature's own laboratory. There are some sixty species of serpents, for example, with deadly venom. Among these, as you doubtless have all heard, none has brought greater terror to mankind than the cobra-di-capello, the Naja tripudians of India. It is unnecessary for me to describe the cobra or to say anything about the countless thousands who have yielded up their lives to it. I have here a small quantity of the venom"—he indicated it in a glass beaker. "It was obtained in New York, and I have tested it on guinea-pigs. It has lost none of its potency."
I fancied that there was a feeling of relief when Kennedy by his actions indicated that he was not going to repeat the test.
"This venom," he continued, "dries in the air into a substance like small scales, soluble in water but not in alcohol. It has only a slightly acrid taste and odour, and, strange to say, is inoffensive on the tongue or mucous surfaces, even in considerable quantities. All we know about it is that in an open wound it is deadly swift in action."
It was difficult to sit unmoved at the thought that before us, in only a few grains of the stuff, was enough to kill us all if it were introduced into a scratch of our skin.
"Until recently chemistry was powerless to solve the enigma, the microscope to detect its presence, or pathology to explain the reason for its deadly effect. And even now, about all we know is that autopsical research reveals absolutely nothing but the general disorganisation of the blood corpuscles. In fact, such poisoning is best known by the peculiar symptoms the vertigo, weak legs, and falling jaw. The victim is unable to speak or swallow, but is fully sensible. He has nausea, paralysis, an accelerated pulse at first followed rapidly by a weakening, with breath slow and laboured. The pupils are contracted, but react to the last, and he dies in convulsions like asphyxia. It is both a blood and a nerve poison."
As Kennedy proceeded, Mrs. Maitland never took her large eyes from his face.
Kennedy now drew from a large envelope in which he protected it, the typewritten note which had been found on Maitland. He said nothing about the "suicide" as he quietly began a new line of accumulating evidence.
"There is an increasing use of the typewriting machine for the production of spurious papers," he began, rattling the note significantly. "It is partly due to the great increase in the use of the typewriter generally, but more than all is it due to the erroneous idea that fraudulent typewriting cannot be detected. The fact is that the typewriter is perhaps a worse means of concealing identity than is disguised handwriting. It does not afford the effective protection to the criminal that is supposed. On the contrary, the typewriting of a fraudulent document may be the direct means by which it can be traced to its source. First we have to determine what kind of machine a certain piece of writing was done with, then what particular machine."
He paused and indicated a number of little instruments on the table.
"For example," he resumed, "the Lovibond tintometer tells me its story of the colour of the ink used in the ribbon of the machine that wrote this note as well as several standard specimens which I have been able to obtain from three machines on which it might have been written.
"That leads me to speak of the quality of the paper in this half-sheet that was found on Mr. Maitland. Sometimes such a half-sheet may be mated with the other half from which it was torn as accurately as if the act were performed before your eyes. There was no such good fortune in this case, but by measurements made by the vernier micrometer caliper I have found the precise thickness of several samples of paper as compared to that of the suicide note. I need hardly add that in thickness and quality, as well as in the tint of the ribbon, the note points to one person as the author."
No one moved.
"And there are other proofs—unescapable," Kennedy hurried on. "For instance, I have counted the number of threads to the inch in the ribbon, as shown by the letters of this note. That also corresponds to the number in one of the three ribbons."
Kennedy laid down a glass plate peculiarly ruled in little squares.
"This," he explained, "is an alignment test plate, through which can be studied accurately the spacing and alignment of typewritten characters. There are in this pica type ten to the inch horizontally and six to the inch vertically. That is usual. Perhaps you are not acquainted with the fact that typewritten characters are in line both ways, horizontally and vertically. There are nine possible positions for each character which may be assumed with reference to one of these little standard squares of the test plate. You cannot fail to appreciate what an immense impossibility there is that one machine should duplicate the variations out of the true which the microscope detects for several characters on another.
"Not only that, but the faces of many letters inevitably become broken, worn, battered, as well as out of alignment, or slightly shifted in their position on the type bar. The type faces are not flat, but a little concave to conform to the roller. There are thousands of possible divergences, scars, and deformities in each machine.
"Such being the case," he concluded, "typewriting has an individuality like that of the Bertillon system, finger-prints, or the portrait parlé."
He paused, then added quickly: "What machine was it in this case? I have samples here from that of Dr. Ross, from a machine used by Mr. Masterson's secretary, and from a machine which was accessible to both Mr. and Mrs. Maitland."
Kennedy stopped, but he was not yet prepared to relieve the suspense of two of those whom his investigation would absolve.
"Just one other point," he resumed mercilessly, "a point which a few years ago would have been inexplicable—if not positively misleading and productive of actual mistake. I refer to the dreams of Mrs. Maitland."
I had been expecting it, yet the words startled me. What must they have done to her? But she kept admirable control of herself.
"Dreams used to be treated very seriously by the ancients, but until recently modern scientists, rejecting the ideas of the dark ages, have scouted dreams. To-day, however, we study them scientifically, for we believe that whatever is, has a reason. Dr. Ross, I think, is acquainted with the new and remarkable theories of Dr. Sigmund Freud, of Vienna?"
Dr. Ross nodded. "I dissent vigorously from some of Freud's conclusions," he hastened.
"Let me state them first," resumed Craig. "Dreams, says Freud, are very important. They give us the most reliable information concerning the individual. But that is only possible"—Kennedy emphasised the point—"if the patient is in entire rapport with the doctor.
"Now, the dream, is not an absurd and senseless jumble, but a perfect mechanism and has a definite meaning in penetrating the mind. It is as though we had two streams of thought, one of which we allow to flow freely, the other of which we are constantly repressing, pushing back into the subconscious, or unconscious. This matter of the evolution of our individual mental life is too long a story to bore you with at such a critical moment.
"But the resistances, the psychic censors of our ideas, are always active, except in sleep. Then the repressed material comes to the surface. But the resistances never entirely lose their power, and the dream shows the material distorted. Seldom does one recognise his own repressed thoughts or unattained wishes. The dream really is the guardian of sleep to satisfy the activity of the unconscious and repressed mental processes that would otherwise disturb sleep by keeping the censor busy. In the case of a nightmare the watchman or censor is aroused, finds himself overpowered, so to speak, and calls on consciousness for help.
"There are three kinds of dreams—those which represent an unrepressed wish as fulfilled, those that represent the realisation of a repressed wish in an entirely concealed form, and those that represent the realisation of a repressed wish in a form insufficiently or only partially concealed.
"Dreams are not of the future, but of the past, except as they show striving for unfulfilled wishes. Whatever