506 Sir W. Eamsay and Dr. B. D. Steele on the 



IV. Temperature that of chlorobenzene boiling under a pressure 

 of 719 mm8. = 129-60°. 



A... lengtli=816 mms. 

 B... „ =172 „ 

 C... ., =118 „ 

 D... „ = 16 „ 



temperature= 8-1° 



= 17-2° to 17-4° 

 = 58-6° 

 = 129-60°. 



anometev ... (1) 993-65 

 +c „ 1-34 

 -hd „ 0-37 

 + 06 „ 006 



(2) 993-62 (3) 993-60 (4) 993-64 

 1-34 „ 1-34 „ 1-34 

 0-37 „ 0-37 „ 0-37 

 0-06 „ 006 „ 006 



X = 995-42 995-39 995-37 995-41 



Point (1) 21-26 (2) 21-26 (3) 21-24 (4) 21-24 



Point(0-1)+/ „ 113-86 „ 113-86 „ 113-86 „ 113-86 



+a ' „ 1-19 „ M9 „ 1-19 „ 1-19 



+b „ 0-54 „ 0-54 „ 0-53 „ 0-.53 



+e „ 1-12 „ 1-12 „ 1-12 „ 1-12 



Y = 137-97 137-97 137-94 137-94 



P = (X-Y) = (1) 857-45 (2) 857-42 (3) 857-43 (4) 857*47 

 +k = „ 2-49 „ 2-49 „ 2-49 „ 2-49 



True pressure „ 859-94 „ 859-91 „ 859-92 „ 859-96 

 Mean pressure = 859*93. 



From the above figures the coefficient of expansion of 

 oxygen between 0° and 100° is fonnd to be 



0-0036694, 



whilst the temperature of chlorobenzene boiling 



at 292-75 mms. is 99-71°; 

 and at 719-00 „ is 129-6°; 



and from comparison with the thermometer in s, the temperature 



at 468-5 mms. is 114-9°, 



all of them being expressed on the oxygen scale of tempe- 

 rature. 



Method of Experiment. 



Before each experiment the volume-tube was carefully 

 washed with distilled water and with pure alcohol and dried ; 

 it was then attached to a Topler pump by means of an india- 

 rubber cork, a tube containing phosphoric anhydride being 

 interposed between the tube and the pump. The side tube a 

 (fig. 1) was attached by a short piece of thick-walled rubber 



