towards a Dynamical Theory of Solutions. 47 



The requisite values o£ A and p for use in (34) have been 

 obtained from Table I. by interpolation, (pi/vi+P2/v-i)p& 

 being at the most only 6 per cent, of ^ft}^Pi/vi~P2/V2- The 

 table shows that Xi/p 2 + x 2 /pi ^ nearly constant throughout, 

 though it starts with a small value and rises to a maximum 

 when jt? 1 = 0*16, increasing again at the largest p x . The main 

 fact then is that X\\p 2 -\- x. 2 fp^ daring the change of trihydrol 

 into dihydrol, is not much different from its value during 

 the change of dihydrol into hydrol. Thus, while the course 

 of viscosity emphasises the total change, it does not differen- 

 tiate sharply the two chief processes of which the change 

 consists. 



The data used for viscosity of the fatty acids in the next 

 table are those of Tsakalotos [Comptes jRendus, cxlvi. p. 1146, 

 1908). 



Table Y. 



At 20°, Viscosity of Water and 



Formic Acid. 



100^ 20-2 40-6 61*1 68-4 74'5 772 871 100 



10 3 p 998-2 1049 1098 1143 1159 1171 1176 1192 1216 



10" 1 // 1003 1108 1246 1430 1480 1.535 1576 1669 1780 



-r-xjp % -xjp\ 10 13 17 15 15 18 19 



Acetic Acid. 



100 ^ 22-3 40-7 50"4 62-2 71*2 779 85-6 100 



10 3 p 998-2 1026 1046 1055 1064 1068 1069 1067 1052 



10 5 > ? 1002 1502 1930 2188 2404 2617 2716 2344 1286 



-*i/p*-*JPi 16 ° 165 174 190 222 262 306 



Propionic Acid. 



\00 Px 346 68-9 74-2 79'8 90 100 



10 3 p. 998-2 1022 1025 1023 1020 1012 994-5 



I0 5 il 1003 1982 2752 2794 2973 2622 1114 



-ct\/ P . 1 -xJ Pl 209 270 302 367 596 



Butyric Acid. 



lOOpx 295 49 68-2 74-6 82-2 89-1 100 



10 V 9982 10060 9986 9933 9889 9856 9779 9852 



io 5 q 1003 2186 3091 3560 3576 3404 3015 1555 



-*i/Pa-*a/Pi ■■ •;• 217 207 228 250 296 379 



This table comprises a helpful range of facts. While 

 formic acid shows no maximum of viscosity, acetic acid has 

 a marked maximum at the same value of p 1 as gives a 



