Isaac Newton has been credited with the first description of conformal interaction observed through the interference phenomenon known as Newton's rings, though it was S. D. Poisson in 1823 who first described the optical characteristics of two identical surfaces in contact. It was not until the 19th century that objects were made of such precision that the binding phenomenon was observed. The clinging together was described as "wringing together", or as "ansprengen" in German. By 1900 optical contact bonding was being employed in the construction of optical prisms, and the following century saw further research into the phenomenon at the same time that ideas of inter-atom interactions were first being studied.