[1] Over the course of his life, de Mairan was elected into numerous scientific societies and made key discoveries in a variety of fields including ancient texts and astronomy.

[5] De Mairan's key conclusion was that the daily rhythmic opening and closing of the leaves persisted even in the absence of sunlight.

[9] A video showing circadian rhythms in a cucumber plant in constant conditions, similar to what de Mairan observed, can be seen here on YouTube.

Despite Marchant's publication of de Mairan's work, which might have suggested the existence of endogenous biological clocks, rhythms in plant movements were for a long time thought to be extrinsically controlled, by light and dark cycles, or magnetic and temperature oscillations, or even a mysterious, yet-to-be identified X-factor.

This was probably the first hint of what is now called the circadian (from Latin circa, about, and diem) nature of such endogenous rhythms, found in practically all living organisms, including some bacteria.

[1] Beyond astronomical and circadian observations, de Mairan actively worked in several other fields of physics including "heat, light, sound, motion, the shape of the Earth, and the aurora".

[1] The following is an abbreviated list of publications (with their English translations) organised by Dr. Robert A. Hatch at the University of Florida:[13][14] He also published mathematical works.