102 Scientific Proceedings, Royal Dublin Society, 



These results led us to hope that the method might (possibly 

 with some modifications) be found capable of employment for 

 quantitative as well as for qualitative analysis. 



The questions we wished to settle by our experiments 

 were : — 



I. Whether, when fused in the reducing flame on charcoal 

 with borax and sodium carbonate, the metals antimony, tin, lead, 

 arsenic, silver, bismuth, copper, nickel, and zinc, could be com- 

 pletely reduced from their combinations with oxygen, with the 

 volatile acids, hydrochloric, sulphuric, nitric, and hydrofluoric ; 

 and also from their combinations with the non-volatile acids, 

 silicic and phosphoric. 



II. Whether, when similarly treated, aluminium, chromium, 

 manganese, cobalt, and iron are wholly non-reducible from their 

 compounds ; the cobalt and iron more especially from their com- 

 binations with arsenic and phosphoric acids. 



III. Whether, when com-plex substances are similarly treated, 

 the constituent metals thereof respectively behave as in simple 

 compounds, or whether their behaviour is modified in any way. 



The subject-matter of the present Paper deals mainly with 

 questions Nos. I. and II. A considerable amount of work has also 

 been done bearing upon question No. III., but it is proposed to deal 

 with this, and with separations by this method, in a further paper 

 by one of us. 



Appended are Tables giving the results of some of our experi- 

 m ents. 



Details of Matstipulation. 



The Charcoal Support. — The pieces should be from 12 inches 

 to 18 inches in length, and from \\ inches to 2 inches in dia- 

 meter, and must be tolerably free from fissures. Our first 

 experiments were made with charcoal of a very fair quality got 

 from Messrs. Grifiin & Son, of London. Later on, some of 

 excellent quality was obtained from Messrs. Harrington, Bros., 

 of Cork. 



The cavity into which the substance is to be introduced should 

 be bored in the end of the stick of charcoal, and its size and shape 

 are of importance. In shape it should be conical, the sides being 



