'280 Proceeding.s of the Royal Society of Victoria. 



iiaineh', that silver wire as now ()l)tained is very mucli 

 more pure, and altogether very much better than what was 

 supposed to be pure silver twenty -five years ago. The 

 metal J\latheson worked with iu making the experiments 

 for the British Association, was supposed to he the purest 

 that could be got, and up to the present that had never 

 been dis|)uted, l>ut after Mr. Steele's work there need be no 

 hesitation in asserting that silver Aviro had been produced 

 in this Colony of a, considerably higher degree of purity 

 than what was supposed to be chemically {)ure some years 

 ago. 



Profi-snr Masson desired to know what steps Mr. >Steele 

 took tii ascertain the degree of purity of his Thallium. He 

 also wished to know how far Mr. Steele's coefficient of specific 

 resistance agreed with Mathesoii's determiii;Uiou of some 

 yeai's ago. 



Ml-. Steele said he was not then in a |:)osition to reply 

 to the ([uestioti relating to the degree of purity of his 

 Thallium. As to the conductivity- of Thallium, the 

 '•Dictionary of Uhenustry" referred to it, hut the results 

 were not given with absolute certainty. According to the 

 fig-nves he had ([Uoted in his pai)er, the conductivity of 

 Thalliuui is slightly better than lead, but a great deal worse 

 than tin. 



Mr. Bl.yckett considered that the lead used by Mr. 

 Steele, being ordinary commercial lead, would have gi\-en 

 better results if it had been purified by re-crystallisation. 



Mr. Steele said that the purity of the lead made no 

 difference. He merely measured the specih'c resistance of 

 lead, and he might have used an alh\y. 



The PiiESiDENT said that the elasticity of the Constants 

 was of interest. 



'vlr. Steele believed that the jjarticular specimen of 

 Thallnmi he had used, was imported into the Colony for 

 the pur[)i).se of having its elasticity tested, and that had 

 been ilone l>y Mr. William Sutherhuid, prioi' to his use of 

 the s{K:'ciu;cn. 



A paper (~»n "'flu; Lichenology of Victoria. Part I," by 

 the Rev. F. R. M. Wilson, was presented by Mr. \V. H. 

 Arclier. F. L.S., and taken as read. 



