Proceedings of Learned Societies. 397 



considerable danger. A glazing material free from these objections, 

 while at the same time it is easily nsed, and very economical, is 

 now employed very advantageously Its action depends on the 

 solubility of the alkaline silicates. The article to be glazed is either 

 brushed over with the alkaline solution, or is immersed in it — a larger 

 quantity of it being absorbed when the latter method is adopted, 

 on account of the porosity of the unglazed article. It is then ex- 

 posed to a temperature which fuses the compounds of silex and the 

 earths. The glazing thus produced has a fine appearance, and is 

 of a most durable kind, being unaffected by caustic liquids or atmos- 

 pheric changes. 



Economic Mode of Reducing Copper. — It consists in the appli- 

 cation of water when the ore is at a high temperature. As soon as 

 the ore has reached a red heat, water is projected upon it in the 

 form of a fine spray, and after the white vapours have escaped, the 

 temperature is raised to that of fusion. With good ore this process 

 is sufficient ; with ores of an inferior kind the product of the first 

 fusion, when it has cooled, is broken in pieces, and the process of 

 heating to redness and applying water is repeated. And when 

 fusion is produced, powdered charcoal and lime are added, the whole 

 being thoroughly mixed. The scoria thus formed is removed, and 

 the process is finished by transmission of atmospheric air through 

 the fused mass. 



Protection of Armour Plates from Corrosion. — The fact that 

 even cast iron may be coated with glazing, by spreading on its sur- 

 face a fusible glass as powder, or, which is better, the materials 

 of which glass is made, and then raising to a proper temperature, 

 has been applied to the coating of iron on the large scale, and it has 

 been proposed to protect armour-plates in this way. The adhesion 

 of the enamel thus produced on the surface of the iron is very firm, 

 since the metal is oxydized, and the oxide combining with some of 

 the constituents of the glass, a compound glass, which adheres 

 strongly to the iron, is formed. If the coating is not too thick, it 

 has but little tendency, even with considerable changes of tempera- 

 ture, to separate from the metallic surface ; and it forms a protec- 

 tive coating which, even under very rough usage, and considerable 

 alterations of temperature, has been found, when skilfully produced, 

 to last for years uninjured. 



PROCEEDINGS OF LEARNED SOCIETIES. 



ROYAL SOCIETY.— May 16. 



" On the Occlusion of Hydrogen by Meteoric Iron." By 

 Thomas Graham, Esq., F.R.S. In a paper communicated to the 

 Society in June last, Mr. Graham has shown that metals under 

 certain conditions absorb and retain gases, each metal exerting a 

 selective power. The author now considers that the investigation 



