304 PROCEEDINGS OF SECTION B. 



The source of the iron rust and the conditions under which 

 it had been found are given in what might appear as 

 unnecessary detail, but full particulars are furnished so that 

 it may be seen that iron of various qualities, e.g., eoramon 

 cast, inferior, and the best malleable iron and steel all furnish 

 rust containing maefnetic oxide in the early stages of the 

 rusting, and that under certain circumstances the final 

 products — the sesquioxide and hydrated sesquioxide of iron — 

 may also be magnetic. 



Metallic iron was tested for in every case by careful 

 examination for specks of metal when grinding in the agate 

 mortar, and also by digesting the powder in a solution of 

 iodine in potassium iodide for some hours, but proved to be 

 absent, except in one or two cases, which are mentioned 

 further on. 



No. 1. — Rust from Iron Rails: Clifton Springs, Port 

 Arlington, Victoria. 



This specimen was collected, as stated above, in January, 

 1889, from the old tramway on the pier at Chfton Springs, 

 Port Ai'lington, Victoria. 



9'1 grammes were crushed and sent through a No. 60 

 sieve. The dark brown powder was wholly attracted by the 

 magnet, the amount of non-magnetic powder left after 

 repeated applications of the magnet being almost invisible. 

 The attempted separation of any non- magnetic matter was 

 repeated time after time, so as to get rid of any entangled 

 non-magnetic dust, but always with the same result. 



The rust was also acted upon by the magnet under water, 

 after re-crushing to an impalpable powder in an agate 

 mortar. This was done to avoid, as far as possible, non- 

 magnetic oxide being lifted mechanically between or by 

 attached particles of magnetic oxide ; but, after many 

 repeated attempts to obtain non-magnetic rust from it, I had 

 to come to the conclusion that it was all attracted by the 

 magnet. 



Another attempted separation was made on 5'640 grauimes 

 powdered in an agate mortar, but with a like result, i.e., the 

 whole was attracted. 



These scales of rust were found to be not only magnetic 

 but some were also polar, i.e., they not only attracted one 

 end of the magnetic needle but also repelled the other, and 

 the opposite edges of the fragments possessed opposite 

 polarities ; moreover, when suspended in a stirrup by unspun 



