6 Jones, Selcnhun and Telliiriuui on Arsine ajid Stibmc. 



blackened all over. The stains were not removed by 

 treatment with either hydrogen dioxide or hydrochloric 

 acid, so that selenium decomposes stibine at the tempera- 

 ture of boiling water. 



\c) In the dark. 



Stibine was passed over powdered selenium contained 

 in a straight glass tube and screened from light. A 

 paper moistened with lead acetate solution was placed 

 between the stibine apparatus and the selenium tube, and 

 another at the exit of the apparatus. When the gas had 

 passed for half an hour the first paper was quite unaltered, 

 but the second was stained half its length. The experi- 

 ment was continued and ultimately the second paper was 

 blackened all over. The stains were not removed by 

 hydrochloric acid, so that, even in the dark, stibine is 

 decomposed by selenium. This reaction was so remark- 

 able and unexpected that the experiment was several 

 times repeated with the same result. Of all the hydrides 

 examined in contact with sulphur, selenium, and 

 tellurium, stibine is the only one to be decomposed in the 

 dark at the ordinary temperature, and then only when in 

 contact with selenium. 



Action of Tellurium on Stibine. 



(a) In sunlight. 



Stibine was passed over powdered tellurium contained 

 in a straight glass tube and exposed to sunlight. The 

 exit tube contained a paper moistened with solution of 

 lead acetate. This paper became darkened after the pro- 

 longed action of the gas, and the stains were not removed 

 when placed in hydrochloric acid, so that stibine is slowly 

 decomposed in presence of tellurium exposed to 

 sunlight. 



