Vapour Density, Moles per Litre. 
166 Proceedings of the Royal Society of Edinburgh. [Sess. 
Ammonium Iodide. 
Temp. 
V.P. 
Vapour Densities. 
Observed, 
g. per c.c. 
Interpolated, 
Moles per 1. 
Calculated (Moles per 1.) 
No Dissociation. 
Complete 
Dissociation. 
300 
33*9 
0-000181 
0-00126 
0-00095 
0-000475 
310 
48-5 
0-00166 
0-00133 
0-000667 
320 
68-4 
0-000307 
0-00212 
0-00185 
0-000926 
330 
95-0 
0-00270 
0-00253 
0-00126 
340 
130-3 
0-000488 
0-00345 
0-00341 
i 0-00170 
350 
176-3 
0-000647 
0-00447 
0-00454 
0-00227 
360 
235-7 
0-000874 
0-00573 
0-00597 
i 0-00299 
370 
311-5 
0-00105 
0-00730 
0-00777 
i 0-00389 
380 
407-3 
000129 
0-00898 
0-0100 
0-00500 
Temp. 300 320 340 360 380 
Fig. 3. 
It will be seen (fig. 3) that in this instance the densities below 340° are 
higher than those calculated for zero dissociation. Above 340° the values 
fall below those for molecular ammonium iodide. This indicates that 
