The Madeleine Smith Story
Since 1857, there have been two schools of thought as to how Emile received his fatal dose of arsenic:
Emile killed himself
At the time of Madeleine's trial, some people felt that Emile accidentally poisoned himself, mistaking the arsenic for some form of medicine. The problem with this theory is that no arsenic (or arsenic container) was found on his body or among his possessions. Also, his name was not found in any Poison Books in the Glasgow, Stirling, or Bridge of Allan areas.
Another theory is that Emile killed himself and purposely framed Madeleine for his death. The lack of arsenic in Emile's possession applies to this theory, too, in addition to other questions:
If Emile killed himself with his own arsenic, how did he know that Madeleine was, coincidentally, buying the exact same poison? (Some have theorized that Emile, in order to frame Madeleine, convinced her to start buying arsenic. But there is not a single piece of documentation or evidence that shows that Emile ever had even a passing conversation about arsenic with Madeleine, let alone a direct attempt to persuade her to buy the poison. None of her letters reflect such a conversation, either and so this theory remains highly speculative.)
If Emile killed himself with his own arsenic, what did Madeleine do with the arsenic she purchased? None of Madeleine's biographers, even those who were clearly pro-Madeleine, believe that she actually used it as a cosmetic arsenic wash, as she stated in her official declaration. Arsenic was sometimes cosmetically used at that time as a solid and used to remove unwanted hair.
Some proponents of this theory state that because none of the coloring matter from Madeleines arsenic was found in Emiles stomach, it could not have been her arsenic they found there. This would be strong evidence if it were true, but at Madeleines trial the physician who performed the autopsy specifically stated: I was not asked to attend to the coloring matter. I did not see it, and I did not search for it. Similarly, the arsenic in Emiles stomach was found inside a dark liquid that may have been cocoa or coffee. But the physicians were not instructed to find out exactly what that liquid was, even though it was clearly present. And a dark liquid might easily hide indigo or soot.
Similarly, some Madeleine supporters have stated that Emile could not have accidentally swallowed that much arsenic in cocoa without distinctly noticing the gritty texture of the poison. However, during Madeleines trial a witness stated that in the few weeks before his death Emile had said, he was not surprised at cocoa not agreeing with him, as he was not accustomed to it. Therefore, as far as Emile knew, cocoa could indeed have been gritty in texture, and he would not have known the difference. Also, this notion rests on the idea that Emile received only a single gritty cupful of the dark liquid, when he might have received smaller doses in several cups.
Madeleine killed Emile
Much of the circumstantial evidence points to this, but there are questions with this theory, too:
If Madeleine was secretly poisoning Emile over the course of several weeks, why did she make her arsenic purchases so blatantly? She even brought an eyewitness with her to one of her purchases.
If Emile suspected that he was being poisoned by Madeleine, as several trial witnesses testified to, why did he continue to take the poisonous beverages from Madeleine?
Even with Emile dead, Madeleine knew that highly damning evidence, her letters to Emile, were still in existence and were bound to be discovered. But she made no attempt to retrieve the letters from Emile's rented room and office.
And so today, Madeleine Smith has taken on a folkloric mystique akin to that of Lizzie Borden. The did she or didnt she? debate continues, and the doubt of her innocence even reached to her legal defender, John Inglis: he was once asked at a dinner party if he truly believed that Madeleine was innocent of the murder charge. After a thoughtful pause, he said simply that he would "rather have danced than supped with her."