A lady whilst walking in a public park was suddenly attacked from behind by a man who was to her an utter stranger. The man inflicted several serious though not dangerous wounds with a pen-knife on the lady and the constable who ran to her assistance.

The act was done without any apparent motive, so the police came to the conclusion that it might have been one of these homicidal inpulses which sometimes follow an epileptic seizure.

It must be remembered that the police are frequently called upon to help people who have had a "fit" in the street, and they are well aware that for a short time after a fit an epileptic is liable to be very violent to those who are near him. Enquiry in this case proved that the man had been under treatment for years for epilepsy at a Nerve Hospital.

A decent sized volume could easily be written on the crimes, mostly of violence, committed by epileptics, and in which a premier place would be given to the crimes of that notorious and mysterious murderer Jack the Ripper.

As the evidence which finally proved the identity of this highly elusive criminal was the result of investigations by a medical man, it might not be out of place to give a few of the facts in connection with those mysterious crimes and their more mysterious perpetrator.

About thirty years ago London was startled by a series of gruesome murders that occurred in quick succession.

So mysterious and so horrible were these crimes that a large number of people in the districts of London in which the crimes happened were too terrified to venture out alone at night.

There were several things in common about all these murders, so that not only the police but the public generally believed that they were the work of one person, and to this hypothetical person they gave the name of Jack the Ripper.

Now there were some remarkably curious features about these crimes.

Firstly, the victims were all women. Then there was the extraordinary rapidity with which the crimes were committed. In at least two cases a policeman on his beat was known to have passed over the very spot where within five minutes later the dead body of the victim was found.

Nor was there any evidence as to whether the murder had been committed where the body was found, or whether the body had been dragged from elsewhere and deposited there.

Was the criminal a man or a woman? Were there two criminals? Of course, the criminologists, amateur and professional, produced a large crop of theories, all of them unsatisfactory. But the majority of these were based on the inference that the deeds were committed by an insane medical student.

The reason for this idea was because in every case the bodies had been subjected to mutilations after death, and mutilations of a character which suggested that the criminal must have had a more than ordinary knowledge of human anatomy.

It was these mutilations that gave rise to the nickname "The Ripper."

The crimes ended with the same suddenness with which they had started, and, curiously enough, were not followed by the usual succession of imitative crimes. Needless to say the police were subjected to a good deal of criticism at their inability to track down this elusive criminal.

But it so happened that the police actually arrested the man. It was not until some twenty years afterwards, however, that the identity of Jack the Ripper was established, and by that time interest in the crimes had died down.

The first step in the train of evidence had been known for some years before its importance was fully appreciated.

Whilst discussing the conduct of a certain patient the ward-orderly was able to give the following piece of information to the medical officer in charge of one of the criminal lunatic asylums.

The orderly for some years had been able to foretell the coming of the patient's "fits," a bit of knowledge which was of great utility, in view of the fact that the patient was an exceedingly violent epileptic. The orderly had noticed that two or three hours before the actual fit took place that the patient would become very restless, wander, muttering to himself, up and down the ward.

After about an hour of this conduct he would ask for a piece of paper and pencil, and when these had been given him he would sit down at the table and draw.

The drawings were invariably of women's figures in various attitudes, and drawn with great care.

As soon as the drawing was completed the man would draw a line somewhere across the figure, but would use his pencil with such force that it frequently tore through the paper. Immediately he had drawn that last line he would have a fit.

The orderly, knowing that the man was going to have a seizure, would make preparations to prevent the man from hurting himself or those around him.

Through lack of appreciation that these drawings might be of importance, the orderly had destroyed them, especially as the man had never asked for them, or even given any sign afterwards, that he was aware that he had drawn them.

The medical officer, however, gave instructions that they were to be given to him in future, for there was just a possibility that they might serve to clear up certain details about the man's case.

In the course of a fe wweeks the doctor was able to collect about a dozen of these drawings. He then set about arranging the evidence from all available sources.

The asylum records showed that the man had been in the institution for nearly twenty years. Originally he had been sent there for observation as to his mental condition, having been arrested for a very violent and unprovoked attack on a woman in a public-house.

It was evident from the beginning that the man was a dangerous epileptic lunatic, and as no relatives had come to claim him he was detained in the asylum as being a danger to the public if not under proper control.

The police had not been able to trace his antecedents, while the man himself, being extremely morose and taciturn, as is so common in the epileptic, had obstinately refused to give any account of himself. Nothing special in what he had said or done in the asylum had given a clue to his past, until the investigation of the drawings.

The first point that was obvious in the drawings was that they had been executed by a person with more more than average skill.

In fact, the accuracy fo the details aroused a strong suspicion that the man had an expert knowledge of human anatomy. There was presumptive evidence that the man had been a professional artist.

Incidentally, it may be here mentioned that it is well-known that eccentricity and even mental instability is frequently found amongst artists of the Bohemiam type.

But why did the man make the last, and quite unnecessary, mark on the drawing, and with such force as to rip the paper?

The word "rip" suggested a theory to the doctor. Was this man the once famous "Ripper"?

Working on this theory, the doctor collected all the medical evidence from the various coroners' records of the series of Ripper crimes. He was able to note that the date of the man's arrest and incarceration in the asylum was only a few days after the last murder had been committed. If the man was indeed the Ripper, this would account fo rthe reason why the crimes had ceased so suddenly, and also provide a clue as to why the police had failed to find the criminal.

The doctor then made a series of drawings and carefully inserted a line showing the position of the mutilations that had been perpetrated on the corpses. On comparing these lines with the rips on the man's drawings he found that they corresponded too accurately to be mere coincidence.

In other words, the man must have somehow gained an exact knowledge of the nature and position of the wounds.

How did he come by this knowledge?

He certainly did not glean it from the public Press, or even from the evidence given by the medical witnesses in the coroner's court, for only the vague statements, such as "an incised wound," occurred in the reports of the evidence. The exact details were only available to anyone having access to the doctor's post-mortem reports.

Furthermore, the murders had been committed in various parts of London - mostly North London - and until the time when the doctor started his inquiry the reports were scattered about in several coroners' districts, so that until the doctor had collected the reports there could have only been one person with a knowledge of all the mutilations, and that was the murderer himself.

No further action was taken in this case, for a certified lunatic cannot, by law, be tried.

This case also illustrates a favourite error of the amateur criminologist. When ever bones or fragments of a body are found, the first explanation suggested is that they were once the property of a medical student who has taken an unusual way of disposing of them.

This "medical student" idea is a survival of the days of the "body-snatchers," who flourished before the passing of the Anatomy Act. The medical expert would be able to tell in a very short time whether the body had been used for anatomical purposes.