266 PROCEEDINGS OF SECTION B. 



into sulphuric acid. After allowing" the gas to escape for 

 some time, that portion of the tube in contact with the iron 

 is carefully heated to dull redness. The iron should remain 

 perfectly bright ; if any colour similar to that produced 

 when steel is tempered be visible at either end there is a 

 leak somewhere, and must be stopped before continuing the 

 experiment. Everything being secure and the iron free 

 from colour, remove or loosen for one second or less the 

 rubber stopper at the distal end of the combustion tube, 

 replacing it gently but firmly in its place. After a few 

 seconds you will notice a ring of colour on the bright iron 

 gradually making its way along the cylinder to the front end 

 of the tube. This colour we all know is due to the iron 

 undergoing oxidation ; but the curious part of the experiment 

 just described is that the oxygen has travelled or diffused a 

 considerable distance against a slow current of hydrogen in 

 the opposite direction. After the colour has reached its 

 maximum it gradually goes away, the oxide being reduced. 

 The experiment may then be repeated. It teaches us a 

 lesson on the care necessary in making connections in 

 gaseous experiments. 



5._0CCURRENCE OF GALLIUM AND INDIUM IN 

 A BLENDE FROM PEELWOOD, NEW SOUTH 

 WALES. 



By 3. B. KIRKLAND, F.C.S., Assistant Lecturer and Demonstrator of 

 Chemistry, University of Melbourne. 



I DESIRE to draw attention to the occurrence of two very 

 rare elements — e.g., Gallium and Indium — in a blende from 

 Peelwood, New South Wales. It is the first time, so far 

 as I am aware, they have been detected in any mineral in 

 the Australian Colonies ; indeed, the former has only been 

 found in one or two places in the world, and is exceedingly 

 rare. For some years past I have been engaged in the 

 examination of the various minerals of the colonies — princi- 

 pally blendes — in order to detect the presence of the rarer 

 elements, those particularly sought after being galHum, 

 indium, and thallium. It is important from a chemical and 

 mineralogical point of view that the localities where such rare 

 metals occur should be known, as it is possible they may be 

 found in quantity, or, again, be associated with new minerals 



