574 Transactions. — Chemistry. 



rows, one on each side of the ic-ray tube, and at varying 

 lateral distances, so that the angle of incidence of the rays 

 varied considerably throughout the series. In the case of 

 those farthest from the tube, and where, therefore, the angle 

 of incidence was comparatively large, nothing but the well- 

 defined and highly-distorted shadow was obtained. Where, 

 however, the angle of incidence was small, the side of the 

 shadow nearest the tube was bordered by a dense crescent- 

 shaped band, varying in thickness from nil to O'Smm. The 

 experiment was repeated, and the same result obtained. The 

 sharpness and extent of this reflexion crescent depended on 

 the temperature of the tube and the angle of incidence. A 

 common brass set gave no such reflexion eflect, probably 

 because their surfaces, though smooth in the ordinary sense 

 of the word, were rough compared to those of the highly- 

 pohshed platinum. A gilded weight gave a shght image as 

 long as it was dry. 



In consequence of this experiment some of Eontgen's 

 earlier experiments were repeated, with the result that glass 

 in the form of powder showed a distinctly greater absorbing- 

 power than the same mass in sheet form. If there were no 

 reflexion or refraction of the rays at the faces of the small 

 pieces of glass the powdered glass and the original plate 

 should both have the same effect. These experiments tend to 

 show that the a:-ray vibrations are probably transverse, and 

 of extremely short period. 



Art. LVIII. — On the Position that Cyanogen holds in re- 

 lation to the Sim])le Badicals, and its Inability to combine 

 directly with Silver or Gold. 



By William Skey, Analyst to the Department of Mines. 



[head before the Wellington Philosophical Society, 26th Atigiist, 1896.'] 



Abstract. 



In this communication I refer to the fact that in 1874 I gave 

 a paper to this Society entitled " On the Analogy of Cyanogen 

 to Oxygen,''' in which I endeavoured to show that this com- 

 pound radical should not, for certain reasons that I stated, be 

 classed as it now is with the haloid elements chlorine, 

 bromine, and iodine, but rather with oxygen ; that, in fact, 

 it is only when it is united with sulphur that we have a 



* Trans. N.Z. Inst., vol. vii., p. 379. 



