TRANSACTIONS OP SECTION B. 569 



planes of its constituent crystal ; this may or may not be accompanied by 

 mechanical twinning. 



2. That iron between the ordinary temperature and 1,000° C. exists in three 

 distinct modifications possessing widely different mechanical properties, and that 

 the temperature-ranges in which these modifications exist are consistent with 

 the identification of these three modifications with the o, /3, and y forms of iron, 

 according to the allotropic theory of Osmond and Roberts-Austen. 



3. That /3 iron, although existing at a higher temperature, is markedly 

 stronger and harder than o iron, and that the a//3 transformation involves a 

 volume-change. 



4. That 7 iron as found in approximately pure iron at high temperatures 

 possesses the characteristic structure and some of the properties of ' y iron ' as 

 found in certain alloy steels. 



Incidentally, the demonstration of the real existence of a hard modification 

 of iron at high temperatures serves to prove the correctness of the contention that 

 the failure to harden pure iron by quenching is due to the difficulty of inhibiting 

 the j3 = a transformation by rapid cooling, except in the presence of carbon. 

 The observed power of /3 iron to resist deformation at S00° C. under a stress 

 which is sufficient to fracture the same section of a iron at a temperature of 

 750° C, taken together with the powerfid softening effect of a rise of temperature 

 of 750°, serves to indicate that if f) iron could be preserved in existence at the 

 ordinary temperature, it would possess a very high degree of hardness and 

 strength, probably quite comparable with that of hardened steel. 



10. Report on Electroanalysis. — See Reports, p. 79. 



Second Division. 



The following Papers and Reports were read : — ■ 



1. An Instance illustrating the Relative Instabilities of the Trimcthylene 



Ring as compared with the Tetramethylene Ring. By Dr. J. F. Thorpe, 

 F.R.S. 



2. The Elimination of a Carboxethyl Group during the Closing of the Five- 

 Membered Ring. By A. D. Mitchell and Dr. J. F. Thorpe, F.R.S. 



3. The Molecular Complexity of Nitrosoamines. By W. E. S. Turner 



and E. W. Merry. 



The aliphatic nitro compounds are known to exist in the liquid condition in 

 a complex molecular condition, and it was an interesting question whether this 

 property of giving rise to molecular complexes was shared by the nitroso com- 

 pounds. The high dielectric constant of dimethylnitrosoamine suggests the 

 probability that this substance was a molecularly complex one. 



Measurements were made of the surface energy of three nitrosoamines, the 

 results showing that the aliphatic nitrosoamines are associated liquids, whilst 

 the aromatic compounds, like the aromatic nitrites and nitro compounds, are non- 

 associated. 



The association in dimethylnitvosoamine is very much less than that in 

 acetamide, a substance whose dielectric constant is very little higher than that 

 of the nitrosoamine. 



4. Molecular Association in Water, illustrated by Substances containing 

 the Hydroxyl Group. By W. E. S. Turner and C. J. Peddle. 



Until the recent work of Meldrum and Turner on the molecular weights of 

 amides in water, the fact that molecular association may occur in aqueous 



