Career
Beginning as an apprentice, rising through freeman to master apothecary in the Worcester Mercer"s Company, he went to London in the early 1690s. Bringing proof of his disfranchisement, dated 23 May 1696, he was examined, and admitted as a licentiate of the Royal College of Physicians on 22 December Colbatch offered his services to the "Charitable Society for relieving the Sick, Poor and Needy" in early 1716, which went on to found Westminster Hospital. While apparently initially successful on a trial involving a dog, the powder caused severe burns without slowing the bleeding when applied to humans.
Colbatch"s detractors claimed this was due to the powder"s caustic nature, while Colbatch claimed it was due to improper application of the medicine to the wounds.
Colbatch resisted the common view that medicines were so-called "alkalies" which countered "acidic" diseases, instead claiming that disease was "alkaline", best treated by "acids". This became a vicious "pamphlet war" between Colbatch and his supporters (Edward Baynard and William Cole) against William Coward, Thomas Emes and others over the acidity or alkalinity of his cures, and over whether the diseases themselves were acid or alkaline.
This public disagreement in turn spawned a spate of satires concerning the so-called "Acidists and Alkalists".