TUAXSAe TIO.XS oi' .S(H IKTH'.S. 209 



Ulectric Welding": W. Ingham. Details were given ot the electric 



welding- prciocss as applit'd inv rcpairintr. at a cost oi i.Ss. a (ktVct in a 

 cast steel valve cliamher which it would have cost ijoo to replace. The 

 repaired valve chaniher. though in sulisefpient use under a working head 

 of ahout r.ooo feet for a jieriod of two months, showed no sign of weak- 

 ness. 



SorTH ArRic.\x .Association of .-\x.\i.vtu\i, ("iikm isrs. — Thursday, 

 August i/tli : J. McCrae. Ph.D., I'.I.C, Vice-Presidciu. in the chair.— 

 "The Standardisation of Acid and .ilkaH": j. A. Campbell. Tlu' author 

 discussed the various methods which have heen suggested for the stan- 

 <lardisation of acids and alkalies, and also the indicators used. — "Poisonous 

 Plants of South Africa'': Dr. J. McCrae. The author pointed out that 

 most of the investigation of these |)lants had heen carried out hy the 

 Imperial Institute, although a little had heen done hy Juritz and Ma'rloth. 

 He outlined the properties of the poisonous suhstances which had heen 

 ohtained from the hard pear tree. Transkei quinine tree, gifthol., Scnecia 

 latifolius. 'Iransvaal tulip. Cape Slangkop. gifthlaar. Mcscnibrianthcmum. 

 Tcpiirosia. Cannabis sativa, and others. 



Royal Society of South Africa — Wednesday, Octoher i8th: 

 L. A. Peringuey, D.Sc. F.E.S., F.Z.S., President," in the chair. — 

 "African .]'Iy.voinycctes'' : Miss A. \'. Duthie. A list of the 

 species of Alyxomycetcs previously recorded tVoni Africa in 

 various journals and monographs, and forms which have heen accessible 

 to or collected hy the author. — " On Hybrid forms in the f/enus Satyrium. 

 with descriptions of two new forms': Miss A. V. Duthie. A descrip- 

 tion of two hyhrids from Tulbagh, one Satyrium crectnni X coriifolium. 

 the other Satyrium ereetum X bicorne. .\ detailed description was given 

 of the vegetative and floral structures in each form. The morphological 

 evidence was supported by observations on the parent forms.- -" ionisa- 

 tion of Gases and the Absorption of Rdntgen Rays'': L. Simons. The 

 independence of X-ray effects of molecular aggregations and the depend- 

 ence only on the atoms present, together with the fact that it has been 

 shown that the absoriition of a given wave length in a solid varies as 

 the fourth power of the atomic number of the solid, whilst for a gas the 

 primary /3 ionisation also varies as the fourth power of the atomic mmiber 

 of the atom ionised, leads to the conclusion that absorption in soluls I apart 

 from scattering) is due throughout to the production of /3 particles. — 

 "Note on the occurrence of Daph>iin in the Arthrosolen" : Prof. M. 

 Rindl. The author has determined the presence of daphnetin and ,gluco.se 

 in Lasios'phon polycephalns. a perennial shrub which flowers in August 

 and September, known to South .African farmers as Januariehosje. He 

 assumes that the glucoside daphnin had been i)resent and was hydrolysed 

 in the process of extraction. 



Chk.mkal. Mktalll'uojcal, and Mixix(; Socif.ty ok South Africa. — 

 Saturday, September i6th : Prof. J. A. Wilkinson, ALA., F.C.S.. President, 

 in the chair. — "Recent advances in chemical, industry" (Presidential 

 address) : Prof. J. A. Wilkinson. Ihc address commenced with a brief 

 survey of improvements made in the production of materials available 

 for industrial chemical operations; after which improvements in the 

 industries themselves were discussed. These included advances in the 

 technical preparation of hydrogen for aerial navigation ; methods of induc- 

 ing combination between atmospheric nitrogen and oxy.gen, hydrogen, 

 metals, and carbides, respectively ; the sulphuric acid and alkali indus- 

 tries ; the chemical industries induced by the utilisation of cheap electric 

 power, and those resulting from the demands for high oxidisers and for 

 efficient illuminants. In the held of organic chemistry, reference was made 

 to synthetic dyes, synthetic drugs, and synthetic perfumes, and to other 

 industries developed from wider applications of the processes of chemical 

 synthesis. — " The valuation of mines " : Prof. R. .A. Lehfeldt. The author 

 discussed the conditions that had to be fuUilled in order that the present 

 worth of a given mine might be a maxinnnn. An e(|uation was found 

 expressing the relation between the life of the mine and the scale of 

 working-. This equation could not be solved directly, but was capable of 

 ready evaluation with the aid of a table of exponentials. — " The man- 



