“Aconite,” I replied without hesitation.

“Yes,” he agreed; “aconite it is, or more probably aconitine. And that, I think, gives us all the information we want. We need not trouble now to make a complete analysis, though I shall have a quantitative examination made later. You note the intensity of the taste and you see what the strength of the solution is. Evidently that lump of sugar contained a very large dose of the poison. If the sugar had been dissolved in your tea, the quantity that you drank would have contained enough aconitine to lay you out within a few minutes; which would account for Mrs. Schallibaum’s anxiety to get clear of the premises. She saw you drink from the cup, but I imagine she had not seen you turn the sugar out.”

“No, I should say not, to judge by her expression. She looked terrified. She is not as hardened as her rascally companion.”