Question about the techniques of Victorian apothecaries -- regarding colchicum

Factual Questions
1

I am researching the 1879 death of a man who apparently committed suicide by taking extract of colchicum – the Autumn Crocus. I have some questions about the preparation of such a tincture and also about the units used.

The active ingredient is colchicine, a powerful poison, whcih has been used as a remedy for gout and other inflammatory conditions since at least Ancient Egyptian times. It is prepared by crushing the seeds or bulb and dissolving it in alcohol, vinegar etc. My first question is how could they have obtained a uniform product – containing a consistent quantity of colchicine. I can see that dissolving a certain number of seeds or weight of raw product in a known amount of solvent would be the first step but this still seems prone to a lot of variation for such a dangerous product. Could they have had methods of testing?

My second question regards the units used for dosage. The newspaper reports I am working from gaily skip from tablespoons to drops to ounces assuming the reader can make sense of it. Primarily I would like to know how much is in a drop.

2

Victorian chemists, as befits that time, were extraordinarily meticulous in their work.
As for drops Wikipedia explains they were kinda a judgement call.
an informal (and incorrect) synonym for minim, the smallest unit of fluid measure in the Apothecaries’ systems of the United States customary units, Imperial units, and pre-1824 English units equal to 1/60 of a fluid dram or 1/480 of a fluid ounce

prior to the adoption of the minim in the early 19th century, the smallest unit of fluid measure in the Apothecaries’ systems of the United States customary units and pre-1824 English units, inexact, but presumed to be equal to 1/60 of a fluid dram or 1/480 of a fluid ounce
Still, so long as measurements are consistent within the measurement system utilized, it all rubs out in the wash.