president's address — SECTION B. 61 



this is afterwards separated out by leaching with hot water 

 as ah'eady described, the silver being separated as metal, 

 while the copper and iron compounds are left as insoluble 

 oxides. This process, known as Ziervogel's, is particularly 

 well suited to argentiferous pyrites carrying from 10 to 40 ozs. 

 of silver per ton. 



Another process of wet extraction has been lately patented 

 by Dr. Storer, of Sydney, and Mr. Marsh, of Broken Hill, 

 which may be briefly described, as follows : — The ore is 

 roasted in a reverberatory furnace along with limestone, the 

 mass lixiviated with water, the zinc preci])itated by magnesia 

 as hydrate, which on filtration yields nearly pure zinc oxide. 



Closely associated with the different processes I have 

 brought before you, as well as with smelting operations 

 generally, is the nature of tie fuel and its snitability for 

 metallurgical work. Mr. J. C. Mingaye, Assayer to the 

 N.S.W. Government, has undertaken a thoi-ough examination 

 of the coals and cokes available in New South Wales, and 

 finds them nearly equal in every respect to those of Europe 

 and America, the exceptions being in the refractory nature 

 of the ash of some specimens, — a defect, however, which 

 is partly compensated for by their greater freedom 

 from the undesirable elements phosphorus and sulphur. 



The phenomenon of solution is, therefore, of world-wide 

 interest, as we see its application in our arts, industries, and 

 manufactures, as well as in the every-day acts of our lives. 

 And all these changes, velocities, rotations, vortices, and pre- 

 cessions, even if we do not as yet perceive them, have been 

 going on under our very eyes from the beginning ; they are 

 still going on in our laboratories and workshops, as well as in 

 the great arena of nature. The truth is, that things con- 

 stantly before us become so commonplace as to no longer 

 awaken our interest as they did in the freshness of youth. 

 Who has not observed the mixed feelings of awe and wonder 

 when some friend comes, it may be for the first time in his 

 life, to witness some natural phenomenon in a laboratory? 

 Do we not find that such an one thus coming fresh upon the 

 scene, untrammelled and free from preconceived notions, sets 

 us thinking by some original and unanswerable question ? 

 There are not wanting among us some who talk of the 

 narrowing tendency of the pursuit of Chemistry as a discipline 

 of the mind. Such a view is totally at variance with fact and 

 experience, since the great issues dependent upon a know- 

 ledge of Chemistry, and the enlarged conception of the 



