The Medical Weakness of the Prosecution
Such was the complete evidence of the cause of death. The quantity of arsenic found in the body was one-tenth of a grain, and upon this evidence rests the first issue the jury had to consider, namely, whether it was proved beyond reasonable doubt that the deceased died from arsenical poisoning.
As to the value of the medical testimony on both sides, Dr. Humphreys admitted that he never attended a case of arsenical poisoning in his life, nor of any irritant poison, and that he would have given a certificate of death from natural causes had he not been told of arsenic found in the meat juice.
Dr. Carter laid no claim to any previous experience of poisoning by arsenic, and was unable to say from the post-mortem examination that arsenic was the cause of death, which he could only attribute to an irritant of some kind, and he admitted that it was the evidence of Mr. Davies, as to the finding of arsenic in the body, which led him to the conclusion that arsenical poisoning had taken place.
Dr. Barron did not see the patient, but assisted at the post-mortem examination, and stated that, judging by the appearances and apart from what he had heard, he was unable to identify arsenic as the particular poison which had set up the inflammation.
Now, assuming for a moment that this issue as to the cause of death rested entirely upon the uncontradicted testimony of these three doctors called for the prosecution, Humphreys, Carter, and Barron, the jury would not have been justified in coming to the conclusion that there was no reasonable doubt that arsenic poisoning was the cause of death. The doctors themselves had admitted that they were unable to arrive at that conclusion, apart from the evidence that arsenic was found in the body. The idea of arsenical poisoning never occurred to them from the symptoms, until the use of arsenic was first suggested.
The doctors could not say that death resulted from arsenic poisoning, and yet the jury have actually found that it did, in the face of the opinions of three eminent medical experts, who say it did not.
Even if these doctors had never been called at all for the defense, the jury were yet not justified in taking the evidence of Drs. Humphreys, Carter, and Barron, in the terms which they themselves never intended to pledge themselves to, namely, to exclude a reasonable doubt that death was due to arsenic.
Let us consider the position of the medical men called for the defense: Drs. Tidy, Macnamara, and Paul are the highest authorities on medical and chemical jurisprudence in Great Britain. No sort of hesitation or doubt attached to the opinions of any of them, and their experience of post-mortem examinations was referred to, as including in the practise of Dr. Tidy, the Crown analyst, some forty cases of arsenic poisoning alone. Dr. Macnamara indorsed the opinion of Dr. Tidy. In addition to that, there was on the same side the evidence of Dr. Paul, professor of medical jurisprudence and toxicology at University College, Liverpool, with an experience of three or four thousand post-mortem examinations. It is impossible to conjecture by what process of reasoning the jury could have come to the conclusion, upon the evidence before them, that it was beyond a reasonable doubt that Mr. Maybrick had met his death by arsenical poisoning.
This volume of evidence before the jury pointed not only to a doubt as to the cause of death, but to a reasonable conclusion that it was not due to arsenical poisoning. It is inconceivable that the jury should have found as they did, except under the mandatory direction of the judge, which left them apparently no alternative but to substitute his opinions and judgment for their own, so that on that issue the finding was not so much the finding of the jury, to which the prisoner was by law entitled, but the finding of the judge, of whom the jury, abrogating their own functions, became the mere mouthpieces.