A ridiculous statement made by Castaing to explain the purchase of morphia and antimony in Paris on May 31 was brought up against him. Shortly after his arrest Castaing had said that the cats and dogs about the hotel had made such a noise on the night of May 30 that they had disturbed the rest of Auguste, who, in the early morning, had asked Castaing to get some poison to kill them. He had accordingly gone all the way, about ten miles, to Paris at four in the morning to purchase antimony and morphia to kill cats and dogs. All the people of the hotel denied that there had been any such disturbance on the night in question. Castaing now said that he had bought the poisons at Auguste's request, partly to kill the noisy cats and dogs, and partly for the purpose of their making experiments on animals. Asked why he had not given this second reason before, he said that as Auguste was not a medical man it would have been damaging to his reputation to divulge the fact of his wishing to make unauthorised experiments on animals. "Why go to Paris for the poison?" asked the judge, "there was a chemist a few yards from the hotel. And when in Paris, why go to two chemists?" To all these questions Castaing's answers were such as to lead the President to express a doubt as to whether they were likely to convince the jury. Castaing was obliged to admit that he had allowed, if not ordered, the evacuations of the sick man to be thrown away. He stated that he had thrown away the morphia and antimony, which he had bought in Paris, in the closets of the hotel, because, owing to the concatenation of circumstances, he thought that he would be suspected of murder. In reply to a question from one of the jury, Castaing said that he had mixed the acetate of morphia and tartar emetic together before reaching Saint Cloud, but why he had done so he could not explain.
The medical evidence at the trial was favourable to the accused. Orfila, the famous chemist of that day, said that, though the symptoms in Auguste Ballet's case might be attributed to poisoning by acetate of morphia or some other vegetable poison, at the same time they could be equally well attributed to sudden illness of a natural kind. The liquids, taken from the stomach of Ballet, had yielded on analysis no trace of poison of any sort. The convulsive symptoms present in Ballet's case were undoubtedly a characteristic result of a severe dose of acetate of morphia.(14) Castaing said that he had mixed the acetate of morphia and tartar emetic together, but in any case no trace of either poison was found in Auguste's body, and his illness might, from all appearances, have been occasioned by natural causes. Some attempt was made by the prosecution to prove that the apoplexy to which Hippolyte Ballet had finally succumbed, might be attributed to a vegetable poison; one of the doctors expressed an opinion favourable to that conclusion "as a man but not as a physician." But the evidence did not go further.
(14) It was asserted some years later by one medical authority in
Palmer's case that it might have been morphia and not strychnine that
had caused the tetanic symptoms which preceded Cook's death.
To the young priest-like doctor the ordeal of his trial was a severe one. It lasted eight days. It was only at midday on the sixth day that the evidence was concluded. Not only was Castaing compelled to submit to a long interrogatory by the President, but, after each witness had given his or her evidence, the prisoner was called on to refute or explain any points unfavourable to him. This he did briefly, with varying success; as the trial went on, with increasing embarrassment. A great deal of the evidence given against Castaing was hearsay, and would have been inadmissible in an English court of justice. Statements made by Auguste to other persons about Castaing were freely admitted. But more serious was the evidence of Mlle. Percillie, Auguste's mistress. She swore that on one occasion in her presence Castaing had reproached Auguste with ingratitude; he had complained that he had destroyed one copy of Hippolyte Ballet's will, and for Auguste's sake had procured the destruction of the other, and that yet, in spite of all this, Auguste hesitated to entrust him with 100,000 francs. Asked what he had to say to this statement Castaing denied its truth. He had, he said, only been in Mlle. Percillie's house once, and then not with Auguste Ballet. Mlle. Percillie adhered to the truth of her evidence, and the President left it to the jury to decide between them.
A Mme. Durand, a patient of Castaing, gave some curious evidence as to a story told her by the young doctor. He said that a friend of his, suffering from lung disease, had been persuaded into making a will in his sister's favour. The sister had offered a bribe of 80,000 francs to her brother's lawyer to persuade him to make such a will, and paid one of his clerks 3,000 francs for drawing it up. Castaing, in his friend's interest, and in order to expose the fraud, invited the clerk to come and see him. His friend, hidden in an alcove in the room, overheard the conversation between Castaing and the clerk, and so learnt the details of his sister's intrigue. He at once destroyed the will and became reconciled with his brother, whom he had been about to disinherit. After his death the brother, out of gratitude, had given Castaing 100,000 francs.
President: Castaing, did you tell this story to Mme. Durand?
Castaing: I don't recollect.
Avocat-General: But Mme. Durand says that you did.
Castaing: I don't recollect.
President: You always say that you don't recollect; that is no answer. Have you, yes or no, made such a statement to Mme. Durand?