144 TRANSACTIONS OF SOCIETIES. 



sivcn I'ibrator " : J. S. van der Lingen. The apparatus described does 

 not involve assumptions of dynamical quantities that the student cannoi 

 determine for himself, and is adapted to give him some definite idea about 

 the acceleration of a freely falling body. Apparatus was also described by 

 which velocities and accelerations may be determined without assuming the 

 time of vibration of some vibrator. — "Note on Astronomical PliotODictry." 

 Dr. J. K. E. Halm. An account was given of a method which claims to 

 derive from the measured diameters of the star discs on a photographic 

 plate the brightness or " Magnitude " of any star on a self-consistent basis. 

 The results obtained for the stars of the Cape x\strographic Zones demon- 

 strate a perfect agreement of the Cape system with the Harvard photo- 

 graphic system. Comparisons between the photographic and visual magni- 

 tudes lead to the conclusion that the "colour" of the stars is a function 

 of their brightness, faint starts being slightly redder than bright stars. This 

 fact is tentatively attributed to the existence of absorbing matter in space. 

 It is also found that, on the average, stars are actinically brighter in the 

 .Milky Way than in other regions. — " The Electromotive Changes accom- 

 panying actiz'ity in the iiiaininalian ('refer": Prof. W. A. Jolly. The 

 neuro-muscular duct leading from the kidney to the urinary bladder was 

 removed from a recently killed rabbit. A glass canula was inserted into 

 the ureter at each end. It was then placed in a moist chamber, kept at 

 body temperature. When warm salt solution is passed at low pressure 

 through the ureter from the upper end, waves of muscular contraction pass 

 over it. Connection with the string galvanometer was made and the deflec- 

 tion of the instrument caused by each wave of activity recorded photo- 

 graphically. The curve resembled in all essentials that obtained from the 

 lieating heart. — "A new Aloe from Swacilaiid" : I. B. Pole-Evans. A 

 new species of Aloe, found in Swaziland by Mr. R. A. Davis, was 

 described and named Aloe suprafoliata. It has rigid, somewhat Heshy 

 distichous leaves. The flower spike is slender, unbranched, and bears 

 rather loosely-attached rose doree flowers. 



Wednesday. August i8th : L. A. Peringuey. D.Sc, P\E.S., F.Z.S., 

 President, in the chair. — "The Grozvth Forms of Xatal Plants": Prof. 

 J. W. Bewfs. The autlior gave a detailed descrii)tion of his work on the 

 growth forms of Natal plants. — " The South African Rust Fungi (i) The 

 Species of Pitccinia on Compositcc " : I. B. Pole-Evans. Descriptions 

 were given of the species of Puccinia based mainly upon material which 

 tlie author and his colleagues had collected during the past ten years in 

 South Africa, and which is now represented in the Mycological Herba- 

 rium at Pretoria. The object of the collection was mainly to elucidate the 

 life-histories of various rusts destructive to economic crops. — " Heating 

 and Cooling Apparatus for Rontgcn Crystallographic Work'': J. S. van 

 der Lingen. The apparatus described was devised by the author to 

 facilitate the work of those who v/ish to carry on research on the deter- 

 mination of the energy of an atom at zero temperature and at verv high 

 temperatures. 



NEW BOOKS. 



Lewin, E. — "The Germans and Africa: then aims on the Dark Conti- 

 nent and how they acquired their African Colonies." pp. xviii, 

 317. Map. London: Cassell & Co. 1915. los. 6d. nett. 



Hartill, Marie. — "Elementary course of South African History to 

 1820." i2mo. Maps and illus. pp. .xiv, 182. Capetown": T. 

 Maskew Miller. 1914. 



Stoneman, Dr. Bertha.— ••p/(/;;f.y and their zvays in South Africa." 

 Crown 8vo. pp. xii, 387. New ed. revised and enlarged. London : 

 Longmans, Green & Co., 1915. 5s. 



