(vi.) 



Pagm 



Art. XI. — Preliminary Observations on Radio- Activity and the 

 Occurrence of Radium in Australian Minerals. By D. 

 Mawson, b.e., Junior Demonstrator in Chemistry, and 

 T. H. Labt, Acting- Demonstrator in Chemistry in the 

 University of Sydney ... ... ... ... ... ... 382 



Art. XII. — Pot Experiments to Determine the Limits of Endur- 

 ance of different Farm-Crops for certain Injurious Substances. 

 By F. B. Guthrie, f.i.c, f.c.s., and R. Helms 390 



Art. XIII.— The Occurrence of Isolated Augite Crystals at the top 

 of the Permo-Carboniferous Upper Marine Mudstones at 

 Gerringong, New South Wales. By H. G. Foxall. (Com- 

 municated by Prof. T. W. E. David, b.a., f.g.s., f.r.s.) ... 402 



Art. XIV. — The Approximate Colorimetric Estimation of Nickel 

 and Cobalt in presence of one another. By R. W. Challinor. 

 (Communicated by Acting Professor J. A. Schofield, f.i.c, 

 f.c.s., a.r.s.m.) 406 



Art. XV. — Note on a Combined Wash-Bottle and Pipette. By 

 J. W. Hogarth. (Communicated by Acting Professor J. A. 

 Schofield, f.i.c, f.c.s., a.r.s.m. ... 418 



ENGINEERING SECTION. 

 Art. XVI. — Tacheometer Surveying with an Ordinary Theodolite. 



By Thomas Kennedy, Assoc, m. Inst, c.e i. 



Art. XVII. — Water Filtration. By J. M. Smail, m. Inst. C.E. ... xin. 

 Art. XVIII. — Filtration of Water at the Hunter District Water 



Works, West Maitland. By J. B. Henson, Assoc.m. Inst. C.E.... l. 

 Abstract of Proceedings ... ... ... ... ... ... i. 



Proceedings of the Engineering Section lxxvii. 



Index to Volume XXXVIII (xxv.) 



