n the
analysis. It doesn't matter much to us, as this analysis is only for our
own information and we can satisfy ourselves as to the state of your
pocket. But bear the rule in mind another time."

We now ascended to the laboratory, where Thorndyke proceeded at once to
dissolve the lump of sugar in a measured quantity of distilled water by
the aid of gentle heat.

"Before we add any acid," said he, "or introduce any fresh matter, we
will adopt the simple preliminary measure of tasting the solution. The
sugar is a disturbing factor, but some of the alkaloids and most
mineral poisons excepting arsenic have a very characteristic taste."

He dipped a glass rod in the warm solution and applied it gingerly to
his tongue.

"Ha!" he exclaimed, as he carefully wiped his mouth with his
handkerchief, "simple methods are often very valuable. There isn't much
doubt as to what is in that sugar. Let me recommend my learned brother
to try the flavour. But be careful. A little of this will go a long
way."

He took a fresh rod from the rack, and, dipping it in the solution,
handed it to me. I cautiously applied it to the tip of my tongue and was
immediately aware of a peculiar tingling sensation accompanied by a
feeling of numbness.

"Well," said Thorndyke; "what is it?"

"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."

"Which is fortunate for you, Jervis. If she had not been in such a
fluster, she would have waited until you had poured out your tea, which
was what she probably meant to do, or have dropped the sugar into the
milk-jug. In either case you would have got a poisonous dose before you
noticed anything am