Plant medicine and the pharmacy

Six plant drugs carry most of the available benefit, and each has a real mechanism:

• Willow and meadowsweet bark — salicylates, for pain and fever. Bark runs from under 1% to around 10% salicin depending on the species, so dose by effect from a weak start.
• Cinchona bark — quinine, for malaria, where it grows.
• Opium poppy — the only strong pain relief you will have.
• Foxglove — digitalis, for heart failure, and the most dangerous thing in this list.
• Honey and garlic — topical antibacterials with modern evidence.
• Aloe — burns and superficial wounds.

Everything else stays out of the pharmacopoeia until it has been recorded as working.

Getting the solvent wrong makes an effective plant useless.

• Infusion — pour boiling water on leaves and flowers, cover, stand 5–10 minutes. Roughly 1–2 g dried material per 200 ml.
• Decoction — bark, root and seed need 15–30 minutes at a simmer, covered, because the actives sit in tough tissue.
• Tincture — 1 part dried material to 5 parts spirit at 40–60% alcohol, 2–4 weeks, shaken daily, then pressed and strained. This is how resins and alkaloids come out, and it keeps for years where a water extract spoils in days.
• Salve and poultice — fat-soluble actives, or a bulk dressing held against skin.

Label every jar with plant, part, date, method and strength.

Plant material varies by species, part, season, soil and individual plant. Without records you are re-guessing every time.

So: scales good to a gram, a fixed recipe per remedy, a dose stated as grams of dried material per kilogram of body weight — not as spoons or handfuls — and a book with a line per dose: who, what, how much, when, and what happened over the following days. This is what writing is for in medicine. Children are dosed by weight, never by a fraction of an adult dose guessed at.

Foxglove is the case that teaches the rule. The effective dose and the fatal dose nearly touch; potency varies widely between plants and even between leaves; and the early signs of poisoning — nausea, visual haloes, a slowing irregular pulse — arrive alongside the signs of benefit. Digoxin is dosed in micrograms in a modern hospital with blood assays available.

Without accurate scales, standardised material and someone watching the pulse hourly, do not use it at all. The same discipline applies to aconite, belladonna, hemlock and datura, none of which belong in a pharmacy that cannot assay.

Most traditional remedies do nothing, and a pharmacopoeia full of inert preparations gives false confidence at the moment it matters most.

So test them. Give the remedy to alternate patients with the same complaint — the odd ones treated, the even ones not — and count outcomes on both sides. Ten pairs will not settle a subtle question; they will settle whether a remedy does anything large. Record the failures with the same care as the successes, and strike from the list anything that does not earn its place. This is controlled comparison applied where it saves the most.

A physic garden of 20–30 m² removes your dependence on wild stands, standardises the material, and puts the plants where the sick people are.

Plant, by preference: willow (cut as coppice), meadowsweet, garlic, aloe, comfrey for poultices, mint and chamomile for gut complaints, calendula for wounds, poppy if the group has decided to grow it. Harvest at the right time — leaves before flowering, roots in autumn, bark in spring — dry in shade at under about 40 °C to preserve the actives, and store in the dark in sealed jars. Dried material loses strength in store, so date every jar and replace it yearly.

The whole pharmacy saves fewer lives than soap, clean water, a latrine and clean childbirth — by a wide margin, and at a fraction of the effort.

So cap it. One or two people, part-time, with a written list, a garden and a record book. If sanitation is unfinished or the water is still unsafe, the person who would have kept the pharmacy is worth more digging latrines. Say this out loud when the group is impressed by medicine: preparing a tincture feels like progress in a way that emptying a latrine does not, and the feeling is wrong.