1 8 On CapiUarUij and its relation to Latent Heal. 



The ilata for sulphuric rether arc, from 14°- 79 to 34°-78 C. 

 column descenda from 35-41 to 32-14 (M. Wolf, Ann. dc 



Chim. vol. xlix. p. 269), hence y = |^ = '09766, ^ = -01060 



(M. Pierre, Ann. de Chim. vol. xv. p. 361) ; hence ^- = 00870, 

 and L = 92'', hence SL=8°-4; and specific heat of aether being 



0-504, we have oq ^ 0^504= ""^^"^^- 

 The data for turpentine are — 



1. From 132" to 165i° C. the column descended from 53 to 



^ = -1856--0127 = -1729, L=G9^ 



Li 



(MM. Fabre and Silberman, Ann. de Chim.), and 8L=13"-1. 

 The specific heat of turpentine being 0-467, we have 



^„ ' ^ =0837 = 8\. 

 33-0 X 467 



2. From 32' to 132"^ C. the column descended from 77 to 53 

 [§ 10] ; hence 



^ = |i=0-3-0, ^=-S=-0337, .„dyi=-33fl; 

 h Qo m 1-060 L 



L=69 + 13 = 82°, and8L = 33-l. Specific heat (assumed same 



as last, though probably it is actually less) 0*467, we have 



§ 20. The relation between capillarity and latent heat— assn- 

 ming it to be proven — enables us to compute the latent heat from 

 the capillarity, and vice versa, e. g. mercury. M. Gay-Lussac de- 

 termined the constant product of the capillarity of this metal to 



4 

 be -0201 = ?x [§ 6], hence Q = 200. From the general equation 



^3 (-^yr§ 13], we have m^(^^h^ = m-'Q.^^h^'^- and 



mQli 3/~9" 132x1072 .R.on? u v, •.> it 



L,= — ^ =A / X jrfTf, =754 [Fahrcnheit'sscale]. 



' '«,Qi V 7-44 200 >- -* 



* The product mQL has the s.ime constant vahie lor all liquids at any 



temperature. 



, 11 f for Fahrenheit's scale is 294330 1 i i • 



Its numerical value | ^^^ eentesimal scale lfi351 6 ) ' '^"^l '" '* ^-^- 



pressed as quotient of atomic weight (on hydrogen scale) by specific gravity, 



L is latent heat expressed in degrees, and Q, as described in §§ 2 and fi, 



has reference to the inch as unit. 



