Oil the Occurrence of Gallium in Clay-ironstone. 303 



current, giving decrease of the quotient A/K; while base favours the 

 A current and disfavours the K current. In other words, the anodic 

 or acidic polarisation is favoured by base, disfavoured by acid; the 

 kathodic or basic polarisation is favoured by acid, disfavoured by base. 

 Anaesthetics (C0 2 ; Et^O ; CHC1 3 ) act like acids and like rise of tem- 

 perature, causing, at certain strengths, a greater relative diminution 

 of A than of K, and therefore a diminution of the quotient A/K tem- 

 porary in the case of C0 2 and Et 2 O, permanent in the case of CHClo. 

 In the weakest dilution that will produce any effect at all there may 

 be increase of A, no increase, or a relatively smaller increase, of K, 

 and therefore increase of the quotient A/K. These effects are, 

 however, at present under examination, and will form the subject of a 

 future communication. The tabular summary (p. 391) will at this 

 juncture be sufficient to enable a comparison to be made between the 

 effects of heat and cold and those of acids and alkalies.] 



" On the Occurrence of Gallium in the Clay-ironstone of 

 the Cleveland District of Yorkshire : Determination of 

 Gallium in Blast-furnace Iron from Middlesbrough." By 

 W. N. HARTLEY, F.R.S., Professor of Chemistry, and HUGH 

 RAM AGE, A.R.C.Sc.L, F.I.C., Assistant Chemist, Royal 

 College of Science, Dublin. Received December 2, Read 

 December 17, 1896. 



In the month of April of this year, we had the honour to submit 

 to the Royal Society* a preliminary notice of the evidence we had 

 obtained of the existence of gallium in the Yorkshire ironstone 

 smelted at Middlesbrough -on-Tees. 



We propose now to give a concise but detailed account of the 

 methods of analysis carried out on the metal and the ore, and the 

 determination of the quantity of gallium present. 



Examination of the Blast Furnace Metal. 



Method of Analysis. The very large proportion of iron rendered 

 the application of some special method of analysis necessary for the 

 separation of metals present in minute proportions, and for the quali- 

 tative and quantitative examinations of the separated substances. 

 We have successfully employed fractional precipitations and the. 

 spectrographic analysis of the precipitates, supplemented by gravi- 

 metric determinations of the purified gallium sesquioxide. 



The sample of metal first received consisted of two small ingots, 

 each weighing about 230 grams ; small pieces, broken with difficulty, 

 * < EOT. Soc. Proc.,' vol. 60, p. 35, 1896. 



VOL. LX. 2 H 



