Homeopathy was introduced by the famous German doctor Samuel Hahnemann. It is a medical science that treats the ailments by medicines which have been tested on healthy human beings and then validated. The basis of Homeopathy is a basic natural principle. In Latin this principle is stated as “similia simlibuscurentur”(let likes be cured by likes) that is to say that to cure any disease a drug must be found which is capable of producing similar symptoms when tested on healthy human. Or in other words a drug can only cure that which it can produce. For example: The onion can also explain the natures law of cure most people struggle with watery eyes and running nose while cutting the onion because of its vapors. If the symptoms occur during an episode of hay fever a dose of 'allium cepa', the homeopathic medicine prepared from onion will cure the symptoms. What the onion can produce in the healthy it will treat in the sick person.