UNIVERSITY OF VIRGINIA PUBLICATIONS 



BULLETIN OF THE PHILOSOPHICAL SOCIETY 



SCIENTIFIC SECTION 



Vol. I, No. 2, pp. 41-44 June, 1910 



ON CHEMICAL INTERACTION OF SUBSTANCES IN THE 

 SOLID STATE.* 



J. W. MALLET. 



Eeference was made to previous investigation in this direction, includ- 

 in the earlier experiments of Spring, of Eoberts-Ansten and of Abel, 

 and of those more recently made by Tamman (Chem. Soe. Abstr., 1909, 

 p. 669), Masing (ditto), Cobb (Chem. Soc. Proc., May 20, 1909, p. 165) 

 and Guillet & Griffiths (Comptes rendus, CXLIX, No. 2). 



In connection with these experiments attention was drawn to the neces- 

 sity for taking note of the possible presence of water (or other solvent) in 

 traces, as derived from the atmosphere, and to the possibility of volatiliza- 

 tion from the surfaces of solids even at ordinary temperature. As bearing 

 on the question of mobility of the particles of solids themselves notice was 

 taken of the various degrees of evident rigidity or plasticity of substances 

 experimented with, and an interesting paper lately published by Beilby 

 (Eoy. Soc. Proc, A. 82, p. 599 — and earlier papers in Brit. Assoc. Eeports) 

 on "Surface flow in calcite" was referred to. 



Some experiments by the author were then described, in which chemical 

 interaction of solids was indicated by change of colour. It was proposed' 

 to dry as thoroughly as possible separate parcels of finely pulverized lead 

 nitrate and potassium iodide in a glass tube which should afterwards be 

 sealed at both ends, the contents to be then shaken together, observing 

 whether the yellow colour of lead iodide should appear, and to make a 

 similar experiment vsdth mercuric chloride and potassium iodide, noting the 

 appearance or non-appearance of the scarlet colour of mercuric iodide. 



*Read before the Section of Mathematical and Natural Sciences, January 18, 1910. 



