Back in 1915, a French surgeon, Prof. Pierre Delbet, M.D., was looking for a solution to cleanse wounds, because he had found out that the traditional antiseptic solutions mortified tissues and facilitated the infection instead of preventing it.
He tested several mineral solutions and discovered that a Magnesium Chloride solution was not only harmless for tissues, but it had also a significant effect over leucocytic activity and phagocytosis; so, it was perfect for external wounds treatment.
Dr. Delbet performed a lot of in vitro and in vivo experiments with this solution and he became aware that it was good not only for external applications, but it was also a powerful immuno-stimulant if taken by injections or even by mouth. He called this effect "cytophilaxis". In some in vivo experiments it was able to increase phagocytosis rate up to 300%. Dr. Delbet serendipitously discovered that this oral solution had also a tonic effect on many people and so became aware that the Magnesium Chloride influenced the whole organism.
In a brief time, he received communications of very good therapeutics effects of this "therapy" from people that were taking Magnesium Chloride for its tonic properties and who were suffering from various ailments.
Prof. Delbet began to closely study the subject and verified that the Magnesium Chloride solution was a very good therapy for an extensive list of diseases.
He obtained very good results in: colitis, angiocholitis and cholecystitis in the digestive apparatus; Parkinson's Disease, senile tremors and muscular cramps in the nervous system; acne, eczema, psoriasis, warts, itch of various origins and chilblains in the skin. There was a strengthening of hair and nails, a beneficial effect on diseases typical of the aged (impotency, prostatic hypertrophy, cerebral and circulatory troubles) and on diseases of allergic origin (hay-fever, asthma, urticaria and anaphylactic reactions).
Then Prof. Delbet began to investigate the relationship between Magnesium and Cancer. After a lot of clinical and experimental studies, he found that Magnesium Chloride had a very good effect on prevention of cancer and that it was able to cure several precancerous conditions: leucoplasia, hyperkeratosis, chronic mastitis, etc.
Epidemiological studies confirmed Delbet's views and demonstrated that the regions with soil richer in magnesium had less cancer incidence, and vice versa.
Reference: http://www.mcs-international.org/downloads/030_magnesium_chloride.pdf