“But surely!” I exclaimed. “You had the evidence of two expert witnesses on the point. What more would you require? What is the difficulty?”
“The difficulty is this. There were several witnesses who testified that when they saw the bottle of medicine, the Fowler’s Solution had not yet been added; but there was none who saw the bottle after the addition had been made.”
“But it must have been added before Mabel gave the patient the last dose.”
“That is the inference. But Mabel said nothing to that effect. She was not asked what colour the medicine was when she gave the patient that dose.”
“But what of the analysts and the post mortem?”
“As to the post mortem, the arsenic which was found in the stomach was not recognized as being in the form of Fowler’s Solution; and as to the analysts, they made their examination three days after the man died.”
“Still, the medicine that they analysed was the medicine that deceased had taken. You don’t deny that, do you?”
“I neither deny it nor affirm it. I merely say that no evidence was given that proved the presence of Fowler’s Solution in that bottle before the man died; and that the bottle which was handed to the analysts was one that had been exposed for three days in a room which had been visited by a number of persons, including Mrs. Monkhouse, Wallingford, Miss Norris, Mabel Withers, Amos Monkhouse, Dr. Dimsdale and yourself.”
“You mean to suggest that the bottle might have been tampered with or changed for another? But, my dear Thorndyke, why in the name of God should any one want to change the bottle?”
“I am not suggesting that the bottle actually was changed. I am merely pointing out that the evidence of the analysts is material only subject to the conditions that the bottle which they examined was the bottle from which the last dose of medicine was given and that its contents were the same as on that occasion; and that no conclusive proof exists that it was the same bottle or that the contents were unchanged.”