Observations on Mesophases or Crystalline Liquids

Having described our present knowledge of molecular arrangement in liquids, we shall now discuss a few data on so-called liquid crystals or mesophases. The existence of such systems was discovered by 0. Leh- 

Ritter and W. A. Sisson, Ind. Eng, Chem., 22, 481 (1930) W. K. Farr and W. A. Sisson, Contrib. Boyce Thompson Inst., 6, 315, (1934) W. A. Sisson, Contrib. Boyce Thompson Inst., 8, 389 (1937) G. L. Clark and E. A. Parker, J, Phys. Chem., 41, 777 (1937) Cf. also H. Mark, J. Phys, Chem., 44, 764 (1939). P. H. Hermans has recently made very interesting contributions to this subject a paper is expected to appear soon. Compare also Naiurwisa, 28, 233 (1940). 

It is possible here only to give a few fundamental data on the nature of the observed phenomena, on their probable causes and on the arrangement of the molecules in the mesophases that can be deduced from them. 

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