Rontgen model

It is difficult to trace the historical development of the theory of water. One of the earliest documents attempting an explanation of some anomalous properties of water is Rontgen s (1892) article, which postulated that liquid water consists of two kinds of molecules, one of which is referred to as an ice-molecule. Rontgen himself admitted that his explanation of the properties of water, using the so-called mixture-model approach, had been known in the literature for some time, but he could not point out its originator. An interesting review of the theories of water until 1927 was presented by Chad well (1927). Most of the earlier theories were concerned with association complexes, or polymers of water molecules. There has been little discussion on the structural features of these polymers. 

There is a long history of the theory of water and aqueous solutions based on various mixture model (MM) approaches. One of the earliest documented explanations of some anomalous properties of water is due to Rontgen, who in 1892 proposed to view liquid water as consisting of two kinds of molecules, one of which he referred to as ice-molecules. The general idea of explaining the properties of water by viewing it as a mixture of species probably originated much earlier. 

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