A language purporting to be that of the inhabitants of the planet Mars, written and spoken by the medium known as Hélène Smith (pseudonym of Catherine Elise Muller). Smith was studied by the celebrated investigator Theodore Flournoy, professor of psychology at Geneva. In 1892 Smith joined a Spiritualist circle, where she developed marvelous mediumistic powers.
In 1896, after Flournoy had begun his investigations, Smith claimed to have been spirited during a trance to the planet Mars, and thereafter described to the circle the manners, customs, and appearance of the Martians. She learned their language, which she wrote and spoke with ease and consistency. Unlike most of the "unknown tongues" automatically produced, the Martian language was intelligible, its words were used consistently, and on the whole it had every appearance of a genuine language.
That it was in any way connected with Mars was, of course, out of the question. The descriptions of that planet and its inhabitants were quite impossible. And the language itself bore remarkable resemblance to French, the native tongue of the medium. The grammar and construction of both languages were the same, and even the vowel sounds were identical, so that the source of the Martian language was clearly an extraordinary construction from the medium's unconscious. As such it greatly resembled the form of religious speech known as glossolalia, or speaking in tongues, which is a new language that is a cutdown version of the language the speaker uses normally everyday.
"Martian Language." Encyclopedia of Occultism and Parapsychology. . Encyclopedia.com. (November 17, 2018). https://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/martian-language
"Martian Language." Encyclopedia of Occultism and Parapsychology. . Retrieved November 17, 2018 from Encyclopedia.com: https://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/martian-language