XX Proceedinc^s. {^April 6tJi, igog. 



(4to., London, 1 797-1 S02), '■'■Gilbert's Annalen der Physik" 

 N.F., I — ^12 (Svo., Leipzig, 1819-1822), '^ Siudies in Analoiny 

 from the Auatoviical Department of Ike Owens Co//e(:;e," vols. 1 — 2 

 (8vo., Manchester, 1891, 1900), and '■'• Studies from the Physio- 

 logical Laboratory of Owens College^'' vol. i (8vo., Manchester, 

 1 891), presented by Mr. Francis Nicholson : ''Swedish Explora- 

 tions in. Spitsbergen, IJ^S — igo8," by A. G. Nathorst and others 

 (Svo., Stockholm, 1909), presented by the Kungl. Universitetets 

 i Uppsala Bibliotek ; '■'• Anatomie dii Corselet et Histolyse des 

 Muscles Vibrateurs, aprcs le Vol i\uptial, chez la Reine de la 

 fourmi (Las'iu^ niger)," Texte et Planches, par Ch. Janet, 2 vols. 

 (Svo., Limoges, 1907), presented by the author; '^ Magnetical, 

 Me/eo?'ological, and Se is nio logical Observations made at the 

 Governme7it Observatory, Bombay and Alibag . . . 1 902-1 905," 

 by N. A. F. Moos (fol, Bombay, 1908), presented by the 

 Governor-General in ("ouncil, India; and '■'■ Comptes Rtndus des 

 Seances de la 1'''' et 2"" Reunions de la Commission Pertnanente 

 de r Association Internationale de Sismologie.. igo6-igo'/P 2 vols, 

 (fol., Budapest, 1906, 1907), presented by Professor A. Schuster, 

 F.R.S. 



Mr. Thomas Thorp, F.R.A.S., presented to the Society a 

 silvered concave grating which he had produced by the method 

 described by him at the meeting held on V'ebruary 23rd, 1909. 



Professor E. Knecht, Ph.D., in a preliminary communica- 

 tion (;n the hydrolysis of gun cotton, stated that, by heating the 

 hexanitrate of cellulose in water contained in a sealed tube to 

 190 C, he had caused it to pass completely into solution. 



Mr. C. E. Stromkyek, M.Inst.C.E., mentioned that he had 

 found that although the nitrogen contained in some samples of 

 steel, analysed for that element, did not miprove the general 

 quality of the steel, it certainly had a very powerful effect on its 

 tenacity ; and he suggested that the difficulties which had 

 hitherto been experienced in harmonising the best results 

 obtained with steels from different works were due to nitrogen, 

 which had not been previously determined for this purpose. 



