This was neater than even Tarleton had expected. I saw positive respect in his eyes.
“Then you have the poison still, Madame, untouched?”
“But yes. I placed it among my little aids to the toilet. You will find it in the cupboard you locked up, you remember.”
“Perhaps you will oblige me by fetching it. Inspector Charles will unlock the door for you.”
The Inspector’s face fell as he rose to escort her. Perhaps he thought that Sir Frank was being deceived. They came back together, Charles carrying the little bottle, which he silently handed to the specialist.
Tarleton went through the form of wetting his forefinger, taking up a few grains of the gray powder and tasting it. His face told nothing.
“The powder now in this bottle is a harmless mixture of charcoal and common salt. The poison that killed Dr. Weathered was upasine.”
Madame Bonnell raised her hands in admirable despair.
“Mille tonnorres! That wretched woman was more mad than I thought. She mistook this stuff for—what did you say, sir?”
The physician shook his head. “You do her an injustice. I have tested her story and I feel no doubt that she placed the real poison in your hands. I have seen the person from whom she took it and from whose brother I obtained some of it myself.”