Page:Proceedings of the Royal Society of London Vol 60.djvu/420

Rh 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 (C02; Et20 ; CH013) act like acids and like rise of temperature, causing, at certain strengths, a greater relative diminution of A than of K, and therefore a diminution of the quotient A/K—temporary in the case of C02 and Et20, permanent in the case of CHC1S. 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.]

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 metaland the ore, and the determination of the quantity of gallium present.

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 qualitative and quantitative examinations of the separated substances. We have successfully employed fractional precipitations and the spectrographic analysis of the precipitates, supplemented by gravimetric 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