234 Mr. A. T. Waterman on the Positive 



Emission from the salt was first detected at 150°, although 

 here it was barely noticeable and soon passed away. At 

 620° it admitted o£ measurement. Some thirty readings 

 were taken, as follows : — 



V. H. M. 



204 1000 B 



T- 



660° 



to 



840° 



e/?n. 



175-5 



to 



224-7 



m/H. 



55 



to 



43 



740° 



241-2 

 232-6 



40-0 

 41-4 



815° 



225-2 

 212-3 



42-8 

 45-4 



830° 



211-8 

 223-5 



45-5 

 43-2 



The values by the balance method at first ranged around' 

 55, coming steadily down as the temperature increased to 43., 



Conclusion. — The values for Al + , Al ++ , and Al +++ would 

 be m/H = 27*l, 13*5, and 9, respectively, so that there is 

 apparently no Al emission at the above temperatures.. 

 Judging by the very low boiling-point the salt could only 

 be in a state of vapour, and the emission above could be 

 accounted for, in part at least, by the distilled water (see §6). 

 It is evident that the K emission is present, but whether the 

 high values by the balance method are caused by the 

 presence of some heavy ion or are due to the motion of 

 the strip is a matter of doubt. 



It is unfortunate that the initial emission beginning with 

 150° was too small and transient to measure. 



5. Platinum Chloride, 



(a) This salt was made by dissolving some clean strips of 

 platinum in aqua regia. The solution was evaporated to 

 dryness and the residue dissolved in distilled water. The 

 washing process was repeated a number of times. %* Grlass 

 vessels were used throughout. A drop of the solution ||was 

 finally placed upon the Pt strip, mounting (fr), which had 

 previously been used for A1F 3 and PbBr 2 . The strip^was 

 glowed for temperatures below 1150°. 



Emission was first detected at 550° and was measurablefat 

 600°. It appeared to decay very rapidly, and measurements 

 were first made at 720°. 



V. 



H. 



M. 



T. 



e/m. 



m/R. 



204 



2460 



B 



723° 



268 



36 









to 



to 



to 









945° 



358 



27 









to 



to 



to 









1100° 



284 



34 



