THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[SIXTH SERIEH] 



JANUARY 1921. 



I. The Properties of Plastic Crystals of Ammonium Nitrate. 

 By W. N. Bond, M.Sc, A.R.C'.Sc, A.Inst. P.* 



[Plates I. & II.] 



THIS paper consists of a description of some experiments 

 performed with crystals of Ammonium Nitrate that 

 exhibit plasticity. The paper may be divided into three 

 parts. In the first, an account is given of experiments on 

 the bending of these crystals; in the second, an account of 

 observations on bent crystals with polarized light. The 

 third consists of a discussion of the results, and of the internal 

 changes accompanying bending. 



Part I. 



The specimens originally used were fine needle-like crystals, 

 produced by Messrs. B runner, Mond and Company. Later 

 some Ammonium Nitrate of French manufacture, from 

 Messrs. Baird and Tatlock, was used for re-crystallizing. 



The long needle-like crystals can be bent and twisted in tl 

 fingers (see PL I. tigs. 1 & 2). If this be done ca-efulh 

 not too rapidly, small loops of diameters of the order of half 

 a centimetre or less can be made. Too rapid bending 



* Communicated by Professor A. W. Porter, F.R.S. 

 Phil. Mag. S. 6. Vol. 41, No. 241. Jan. 1021 B 



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and 



