“When this was communicated to Mr. Vaughan, he was confirmed in his suspicions, and wrote to the elder Mr. Boyes suggesting an enquiry. Mr. Boyes was naturally very much shocked, and said at once that the matter should be taken up. He had known of the liaison with Harriet Vane, and had noticed that she did not come to enquire after Philip Boyes, nor attend the funeral, and this had struck him as heartless behavior. In the end, the police were communicated with and an exhumation order obtained.
“You have heard the result of the analysis made by Sir James Lubbock and Mr. Stephen Fordyce. There was a great deal of discussion about methods of analysis and the way that arsenic behaves in the body and so on, but, I think we need not trouble too much about those fine details. The chief points in the evidence seemed to me to be these, which you may note down if you care to do so.
“The analysts took certain organs of the body—the stomach, intestines, kidneys, liver and so on, and analyzed portions of these and found that they all contained arsenic. They were able to weigh the quantity of arsenic found in these various portions, and they calculated from that the quantity of arsenic present in the whole body. Then they had to allow so much for the amount of arsenic eliminated from the body by the vomiting and diarrhoea and also through the kidneys, because the kidneys play a very large part in the elimination of this particular poison. After making allowance for all these things, they formed the opinion that a large and fatal dose of arsenic—four or five grains, perhaps, had been taken about three days before the death.
“I do not know whether you quite followed all the technical arguments about this. I will try to tell you the chief points as I understood them. The nature of arsenic is to pass through the body very quickly, especially if it is taken with food or immediately following a meal, because the arsenic irritates the lining of the internal organs and speeds up the process of elimination. The action would be quicker if the arsenic were taken in liquid than if it were taken in the form of a powder. Where arsenic was taken with, or immediately on top of a meal, nearly the whole of it would be evacuated within twenty-four hours after the onset of the illness. So you see that, although the actual quantities found in the body may seem to you and me very small indeed, the mere fact that they were found there at all, after three days of persistent vomiting and diarrhoea and so on, points to a large dose having been taken at some time.
“Now there was a great deal of discussion about the time at which the symptoms first set in. It is suggested by the defence that Philip Boyes may have taken the arsenic himself at some time between leaving Harriet Vane’s flat and hailing the taxi in Guilford Street; and they bring forward books which show that in many cases the onset of symptoms takes place in a very short time after taking the arsenic—a quarter of an hour, I think, was the shortest time mentioned where the arsenic was taken in liquid form. Now the prisoner’s statement—and we have no other—is that Philip Boyes left her at 10 o’clock, and at ten minutes past he was in Guilford Street. He was then looking ill. It would not take many minutes to drive to Woburn Square at that hour of night, and by the time he got there, he was already in acute pain and hardly able to stand. Now Guilford Street is a very short way from Doughty Street—perhaps three minutes’ walk—and you must ask yourselves, if the prisoner’s statement is correct, what he did with those ten minutes. Did
