142 



Dr. J. Monckman. The Specific 



bottle from the difficulty of preserving the bottle on remeiting the 

 sulphur, a tube was used shown in the figure at A. The capacity of 

 the bulb was 13' 6 cm, The second vessel contained sufficient mercury 

 to cover the bulb of A, and the stem to the point to which the sulphur 

 rose on heating. 



The bulb was filled with sulphur, and the whole of it kept beneath 

 the surface of the mercury except when a reading was taken. 

 From several series of experiments the curve was prepared. 



.^120 30 40 50 60 70 SO 90 200 10 20 3 40 50 60 70 80 90 300' 10 20 30 40 50 



Temp™ , ..... \ 



Chemical Affinity. 



If the changes previously noticed are produced by some change in 

 the molecules of the element, it will probably show itself in the action 

 of sulphur when strips of metal are exposed to its attack. We know 

 that some metals are acted upon at ordinary temperatures in a slight 

 degree, and with increased energy as the temperature rises. Others 

 do not appear to be changed until a high point. It therefore appeared 

 probable that by carefully watching strips of different metals exposed 

 to sulphur at various temperatures, it might be discovered whether 

 there was any point of sudden increase, and if so what relation it bore 

 to the curves already obtained. 



A test tube was used for the sulphur, and a strip or piece of the 

 metal having been placed in it, the tube was immersed in heated 

 mercury. 



Temperature. 

 120° 0. . . . 



180 c 



245 to 270 c 



After expelling all the air by a stream of coal-gas, 



sodium was dropped in. Took fire. 

 Heated four hours with occasional shaking. 

 Hg, Cu, and Pb slowly attacked. 



Mg, Zn, and Sn not. 



Hg formed a dark malleable mass, filled with globules 



of the metal. 

 Cu more readily acted on. 



