We all know Dr. Samuel Hahnemann as the founder of Homoeopathic System of Medicine. The whole concept of homoeopathy is based on the laws and doctrines propounded by him namely the Law of Similars, Minimum Dose, and Single Remedy, the doctrine of Potentisation, doctrine of Vital Force, Drug Proving, Individualisation and Miasms.
The leech was indispensable in 19th Century medicine for bloodletting, a practice believed to be a cure for anything from headaches to gout. Leeching was largely abandoned as medical science advanced. Dr. Samuel Hahnemann, who first condemned the method of using leeches in treating the patients.