Nature cure was a system for treating diseases with natural agents such as water, diet, herbs and sunshine which developed in nineteenth-century Europe. Natural therapies have been used to treat disease since ancient times. Indeed, the earliest doctors had little to work with other than herbs, foods, water, fasting and tissue manipulation. From Lindlahr's perspective, nature cure is a system of man-building in harmony with the constructive principles in nature of the physical, mental and moral planes of being.
History of Nature Cure
One of the early contributors to natural living and healing was Arnold Rikli (1823 – 1906) who practiced in Germany and Switzerland. He is considered the founder of the light and air cures. He extended the therapy, stating: “Water is good; Air is better; Sun is best.” This seemingly obvious remark was startling to his European countrymen at a time when hygiene had become unknown and it was customary not to expose any area of the flesh to public view, nor to the air and sun! He introduced the concept of contrast water baths, used steam for treating colds and other diseases and was famous for his sun baths which consisted of simply exposing the body to the sun. He also emphasized the importance of walking barefoot on the grass, especially when there was dew on the ground to aid in the drainage ability of the body. He stated  "[that it was] extremely injurious to harden the head by keeping it bare, and on the other hand to keep the feet covered all the time, as people suffering from headache are prone to do . . ."
In 1891 Louis Kuhne (1823 – 1907) wrote The New Science of Healing which was one of the greatest work of basic principles in natural healing. Kuhne advocated sun, steam baths, a vegetarian diet, and whole-wheat bread. His book was one of the first to constitute a true scientific philosophy for the application of all Drugless Methods. He was the first to give to the world the comprehensible idea of pathology and the first to proclaim the doctrine of the “unity or cure.” His book Facial Expression gives the means of diagnosing a patient’s pathological condition and determining the amount and location of the systemic encumbrance. Just as one of Hippocrates’ main tenets was “cocotion”, meaning the body’s ability and intent to isolate and discharge morbid or toxic wastes via skin, mucous membranes, bowels, kidneys, etc., the European Nature Curists such as Louis Kuhn emphasized the “unit of disease” theory stating that “disease is the presence of foreign (morbid) matter in the body . . . cleanliness only cures,” The clinical observation of the “healing crisis” in which the body throws off its toxic accumulation with an acute episode (Hippocratean “coction”) was emphasized by Adolf Just (1859-1936) in his book Return to Nature. Just also promoted self-care and responsibility, stating “Nature does not err”. He is also stated, "Men who no longer listen to the voice of nature become the victims of a thousand different diseases and miseries." 
Heinrich Lahman (1860 - 1905) was trained as medical doctor, but did not ascribe to the many of the beliefs and practices of conventional medicine and he became known as one of the first scientific nature doctors. He became a staunch advocate of natural healing and spent much of his time refuting the practice and false ideas of medical science. He was a strong believer in the light and air cure and constructed the first appliances for the administration of electric light treatment and baths. He emphasized raw food, no salt on foods, no water with meals, and he promoted the steaming of vegetables as well as the use of vegetable extracts and soy and almond milk. He authored many books on diet, heliotherapy and nature cure including the first scientific treatise on Nature Cure in 1891.
Ragner Berg, an American physician emphasized a vegetarian diet and the acid/alkaline effects of food on pH balance of the body, a concept still used effectively by many naturopathic physicians. The Swiss physician, Max Edwin Bircher, opened a diet/sanitarium in 1887 that focused on the use of raw foods, muesli, and a decreased protein intake. Also of note were Platen, Schuessler, Orbel, and Henself as well as Arnold Ehret, whose Mucusless Diet Healing System is still in print.