738 Meeting of the British Association. [Oct., 



power of the metal. Messrs. A. and H. Parkes, of Birmingham, appear 

 to have been working for many years under a patent, in which the 

 advantage of using phosphorus in order to secure a sound casting in 

 copper is a special feature. 



A communication " On Silicium in Iron," and two other papers of 

 minor interest by Dr. T. L. Phipson, were read, and afterwards com- 

 mented upon by several speakers. The general expression appeared 

 to be adverse to the opinion advocated by Dr. Phipson, viz. that the 

 physical characters of iron and steel are mainly determined by the 

 state of combination of the silicium, which it is asserted may exist in 

 the metal in two distinct modifications. Dr. A. Voelcker described 

 an interesting specimen of Boiler Deposit, which was said to contain 

 a considerable proportion of hydrate of magnesia in association with 

 sulphate of lime. The same author likewise directed attention to 

 some Phosphatic Nodules, lately discovered at Nant Gwynnant, North 

 Wales. 



Dr. Angus Smith exhibited a simple form of apparatus for deter- 

 mining the presence of carbonic acid in vitiated air, which he found 

 particularly applicable to the testing of the atmosphere in factories and 

 mines. An india-rubber ball, connected with a bottle holding baryta 

 water, served, by passing through the liquid a definite volume of air 

 to be tested, to indicate roughly the amount of carbonic acid present 

 in the air. The point of first formation of an opalescence, or 

 permanent precipitate, was that which guided the operator, after a 

 few comparative trials, to a knowledge of the degree of purity or 

 contamination. 



Professor A. W. Williamson's report " On the Gases evolved 

 from the Bath Waters," gave rise to an animated discussion upon 

 certain difficulties of gas analysis, particularly the production of 

 carbonic oxide whenever pyrogallic acid was used to absorb oxygen 

 from a gaseous mixture. Dr. Crace Calvert, in a paper entitled 

 " Notes on the Action of Acids on some Metals and Alloys," de- 

 scribed the conditions under which zinc, copper, and brass are soluble 

 in sulphuric acid of different degrees of dilution. 



The preparation of a material called " Parkesine " was briefly 

 described by Mr. Owen Rowland, and its use for coating telegraphic 

 wires advocated on account of its great insulating properties. It was 

 superior in these respects to gutta-percha, india-rubber, or ebonite. 

 Dr. Finch described certain methods of " Utilizing Blast Furnace 

 Slags," which were said to be practised in France and Germany. 

 The waste material was cast in the form of huge rectangular blocks, 

 which after being slowly cooled were trimmed by the mason and used 

 for street paving. The presentation of the Report of the Committee 

 on Gun-cotton was deferred until next year ; Mr. Manning Prentice 

 gave, however, a short account of the manufacture of Gun-cotton at 

 Stowmarket, and described an improved method of preventing its 

 decomposition by keeping it always moist. He recommended the use 

 of Gun-cotton cartridges for sporting purposes, and stated the leading 



