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of these, he concludes that anisotropic liquids are in many- 

 ways analogous to uniaxial crystals, particularly with reference 

 to properties such as double refraction, dichroism and electrical 

 conductivity. There are, however, certain definite differences 

 which are probably connected with the nature of the units, the 

 element of the anisotropic liquid being molecular and that of 

 the crystal atomic. There is no evidence that the molecules, 

 even when arranged in parallel directions, are in the form of a 

 space-lattice. The fact that the external forms of anisotropic 

 liquids have no connection with ordinary crystal faces, which 

 seems to be justified by the work by Grandjean and Friedel 

 {Compt. Rend. 151, pp. 442-4, 19 10) is due to the difference 

 between the cohesive forces in the two cases ; in the latter there 

 is the strong " chemical affinity " between the atoms, in the 

 former the weaker attraction between contiguous molecules. 

 Hence the external form of the liquid approximates to a sphere. 



Moll and Ornstein {Proc. Akad. Wetensch. Amsterdam 19, 

 pp. 1315-27, 191 7) have by means of a thermopile and galvano- 

 meter, devised a new method of determining the extinction 

 of anisotropic liquids and have investigated the effects of both 

 longitudinal and transverse magnetic fields. They find that 

 the crystals tend to be orientated in the direction of the lines of 

 force, but that the glass walls of the tube and temperature-effects 

 introduce perturbing forces so that the extinction is variable. 



Svedberg {Ann. Physik. 49, pp. 437-55, 191 6) has measured 

 the electrical conductivity of various anisotropic liquids at 

 different temperatures, and a theoretical discussion of his 

 results is given by Voigt {ibid. 52, pp. 222-8, 19 16). The former 

 {Kolloid Zeit. 18, pp. 54-6, 101-6, 1916, 20, pp. 73-6, 191 7, 

 21, pp. 19-21, 191 7; from Jour. Chem. Soc. 110, p. 306, p. 383, 

 191 6, 112, p. 249, p. 439, 191 7) has investigated some chemical 

 reactions in anisotropic solvents. The velocity of reaction 

 measured by means of the electrical conductivity changes 

 abruptly at the temperature of isotropic fusion, and is also 

 diminished when the liquid is under the influence of a magnetic 

 field. 



Lehmann {Ann. Physik. 51, pp. 353-90, 191 6) describes the 

 modifications of homogeneous anisotropic liquids induced by 

 spirally twisting the solid previous to the formation of the 

 liquid phase. The same author {ibid. 52, pp. 445-77, 527-40, 

 541-52, Science Abs. 20, A. p. 446) deals with the structure 



