454 Prof. Potter on the Definition of the Temperature of Bodies, 



V 



Then, having given Vj = V +p— °^, we ought to be able to 



calculate V 2 and V 3 , if the expansion is uniform, from the formula 

 V==V e a '°. Then putting unity for the degrees between the 

 freezing- and boiling-points of water, or £° = 1, we have given 



V i =V °- €a = V °( 1 + 55^/ 



- a=:l0g Xffi) =,()178576 



V 2 =V .e 2 «=V e 0357152 



•0357152= log e Qr) = log, (1-03636) 



V 2 =V (1 -03636) 

 V 1 =V (1-018018) 



and 

 or 



and 



= •018342 = 



•• v — 54 . 53 



1 



which is a little smaller, but very near 3 found by Dulong 



and Petit with the air thermometer as ordinarily graduated. 

 Again, 



V 3 = V .€ 3 «=V 6 053 ™ 



or 



and 



•053728 = log/^A =log e (1-05503) 



V 3 =V (1-05503) 

 V 2 =V (1 -03636) 



^-^- 2 = -01867= 



V 53-56 



which, again, is a little smaller, but very near , the quan- 



tity found by Dulong and Petit with the air thermometer. 



That liquid mercury is subject to the law of uniform expan- 

 sion, and its volumes are in a geometrical progression for incre- 

 ments of temperature in arithmetic progression, is evident ; but 

 it is an empirical result only. We cannot expect the compound 

 liquids, as water, alcohol, ether, &c v to follow the same law 



