“I'm asking this question only for our own information; you won't be asked to swear to it in court. What amount of hyoscine do you think was in the body, altogether? I mean, judging from the results you obtained yourself.”
Markfield considered for a moment.
“I'm giving you a guess, but I think it's fairly near the mark. I wouldn't, of course, take my oath on it. But the very smallest quantity, judging from my results, would be somewhere in the neighbourhood of seven or eight milligrammes.”
“Have you looked up anything about the stuff—maximum dose, and so forth?” Sir Clinton inquired.
“The maximum dose of hyoscine hydrobromide is down in the books as six-tenths of a milligramme—about a hundredth of a grain in apothecaries’ weights.”
“Then she must have swallowed ten or twelve times the maximum dose,” Sir Clinton calculated, after a moment or two of mental arithmetic.
He paused for a space, then turned again to Markfield.
“I'd like to see the hyoscine in your store here, if you can lay your hands on it easily.”
Markfield made no objection.
“If you'd come in yesterday, the bottle would have been here, beside me. I've taken it back to the shelf now.”