xvi. Proceedings. [/i//-// 29///, 191 9. 



General Meeting, April 29ih, 1919. 



The President, Professor G. Elliot Smith, M.A., M.D., F.R.S., 

 in the Chair. 



Mr Eric N. Allott, Balliol College, Oxford ; Dr. Edward 

 Ardern, F.I.C, Chief Chemist to the Rivers Committee, 

 Manchester Corporation, Priors Lee, Urmston, near Manchester : 

 Mr. Lionel Blundell, Assoc. M.C.T., Aniline Dye Manu- 

 facturer, Hillside, Prest^vich Park, Manchester ; Mr. Louis 

 Anderson Fenn, B.Sc, Research Physicist to Messrs. Isaac 

 Braithwaite & Son, Kendal, Dalton Hall, Victoria Park, Man- 

 chester ; Mr. Samuel Ernest Melling, F.LC, Public Analyst, 

 County of Chester, Boroughs of Congleton, Wigan, etc., The 

 Cliff, Higher Broiighton, Manchester ; and Professor Frank 

 Lee Pyman, D.Sc, Ph.D., Professor of Technological Chemistry, 

 The College of Technology, ^Manchester ; were elected Ordinary 

 Members of the Society. 



Ordinary Meeting, April 29th, 19 19. 



The President, Professor G. Elliot Smith, M.A., M.D., F.R.S., 

 in the Chair. 



A vote of thanks was accorded the donors of the books upon 

 the table. These included three papers : ''' Parallels in Dante and 

 Milton'" (8vo., Manchester, 191 7), ''''Curiosities in the Divina 

 Co?nmedia" (8vo., Manchester, 1918), and ^^ James Joseph 

 Sylvester" (8vo., Manchester, 19 19), by C. L. Barnes, M.A. ; 

 and " Marine Boiler Alanagement and Construction " (j//z edit.), 

 (8vo., London, 191 9), by C. E. Stromeyer, M.Inst.C.E. 



A paper entitled " Some Features in the Growth of 

 Crystals '* was read by Sir Henry A. Mikrs, ALA., D.Sc, 

 F.R.S. 



The author stated that crystals not only change their form 

 during growth by the development of new faces, but often display 

 a tendency to appear first as needles and then in regular forms, 

 seeming to pass through two stages. Experiments were made by 

 the author many years ago in an attempt to determine the con- 

 centration of the solution in contact with a growing crystal, 

 the refractive index being measured by the method of total 

 internal reflection. These experiments led to the conclusion that in a 

 cooling supersaturated solution stirred in an open trough, a sudden 

 change in refractive index takes place at a definite temperature 

 and that this is due to the sudden appearance of new crystals or 

 to th(j suddenly increased growth of the crystals already present. 

 Enclosed in a sealed tube and shaken, the solution yields a shower 

 of crystals at this tem[)erature alone, althougii, for example, in the 

 case of sodium nitrate, it is about 10 degrees below that of 



