96 
PROFESSOR W. RAMSAY AND DR. S. YOUNG 
numbers first given for the lower temperatures, and probably for 330° may be con¬ 
sidered as correct. 
The mean results at 320° and at 340° are :— 
Temperature. 
Pressure. 
millims. 
320 
444-7 
340 
759'6 
Some of the experiments described above were made with ordinary commercial 
ammonium chloride; but the later ones were all made with material prepared from 
pure hydrochloric acid and “volcanic” ammonia, which, as is known, is free from 
hydrocarbons. 
48. Temperatures of Volatilization of Ammonium Chloride. 
A very clear block of commercial ammonium chloride was cut into pieces of suitable 
size, each of which was drilled with a hole to receive the bulb of the thermometer, 
and was then cut into a cylindrical shape. Owing to the very high temperature 
attained by the ammonium chloride, and the sudden heating, the thermometers were 
frequently broken; each thermometer was carefully calibrated before air was intro¬ 
duced, and their readings served so far to check each other. Although this method 
appears somewhat crude, yet the concordance of the results to be given shows its 
reliableness. 
Series I.—Pressure Raised by Admission of Air. 
Pressure. 
Temperature. 
Pressure. 
Temperature. 
Pressure. 
Temperature. 
millims. 
O 
millims. 
O 
millims. 
o 
5-9 
199-3 
65"0 
256-6 
449-8 
315’5 
6-2 
202-5 
74-9 
259-0 
495-2 
319-4 
30-2 
237-9 
8P9 
262-6 
520-1 
320-5 
37-9 
240-7 
89-8 
264-1 
596-6 
325*6 
38-1 
241-3 
100-6 
267-7 
640-9 
327-7 
45-6 
247-8 
109-9 
269-9 
709-6 
331-3 
59-9 
252-8 
122-1 
273-3 
760-3 
333"4 
1 
