334 
ON EVAPORATION AND DISSOCIATION. 
Mais toutes les experiences par ebullition, qui correspondent a cles temperatures 
inferieures a 100°, donnent des points qui sont tres-inferieurs a la courbe, comme si la 
vapeur du liquide bouillant avec soubresauts etait surechauffee. Je n’ai pas juge 
utile de calculer une seconde formule pour lacjuelle les temperatures seraient prises 
sur le thermometre a air.” He evidently did not consider his results very trust¬ 
worthy ; and this is borne out by the fact that he did not determine the specific heat 
of the liquid, or its heat of vaporisation. 
In conclusion, we append a Table of comparative results, including recent deter¬ 
minations by Dittmar, as well as those by Perkin, Regnault, Schiff, and Ramsay 
and Young. 
Boiling-point. 
Regnault . . . . 
Perkin. 
Schiff. 
Dittmar. 
Ramsay and Young . 
(calculated) 66‘78. 
(observed) 65 - 8-66'0. 
(observed) 64’8. 
(calculated) 64"97. 
(calculated) 64"90. 
Y APOUR-PRESSURES. 
Temperature. 
Regnault. 
Dittmar. 
Ramsay and Young. 
O 
in ms. 
mins. 
rums. 
0 
2682 
29-7 
29-60 
10 
50-13 
53-8 
54-22 
20 
88-67 
94-0 
95-10 
30 
149-99 
158-9 
160-28 
40 
243-57 
260-0 
260-47 
50 
38P68 
409-4 
409-47 
60 
579-93 
624-3 
625-10 
65 
707-33 
761-0 
763-15 
Regnault’s and JJittmar’s results were obtained by the statical method; ours by 
the dynamical method. (See also our observations at 40° and 60° by statical method, 
p. 332.) 
Specific gravity at 22*94°. (Water at 4° = P00000.) 
Dittmar .(calculated) • 78897. 
Perkin ..(calculated) -78908. 
Ramsay and Young .(observed) -78909. 
Specific gravity at 64'8° 
Dittmar .(calculated) -74795. 
Schiff .(observed) "7476. 
