

620 Mr. Bernard Cavanagh on 



so that 



ylr = M \Xc 6 — RSc 0i log m c + =- log (1 +~ 2ci) 



4- 2w! [<^>i — R log Wi ci + R log (1 -h m Sci) ] 



+ EM %y 2 ( ¥2 .. .) ■ (51) 



We have assumed m , c c . . . to be dependent only on 

 temperature and pressure, so that we can include — R logm 

 under the symbols <fi^ (j) 2 etc., and we can write 0m for the 

 quantity Sc (4>o — Rlogm c ) getting 



^ = M |"(/)m + ==- log (1 + moled I 

 L m o -» 



+ 2w 1 ^ 1 -R|logCi — log (l + WoScj)! j 



+ RM 2*//x(c lCs . ..)• • • (52) 

 Thence we have 



££-*.+ |io 8 (i+»„ 2c o + R2*/[/*-s4f ] j 



and }• (53) 



|* =^-R{log Cs -log (l + moScO-S^'U } j 



We have treated m , c cq , . . . ., as dependent only on 

 temperature and pressure. 



J n a solvent which is a mixture o£ inert non-associated 

 liquids these quantities will clearly be independent even of 

 temperature and pressure. The modification just given will 

 of course apply and be useful here, but might be dispensed 

 with since the exact molecular constitution of such a solvent 

 could readily be determined. In a polymerized solvent 

 m c c «... depend on the chemical equilibrium between 

 the different molecules of the solvent, which in the general case 

 cannot be assumed to be entirely independent of c\ c 2 , . . . 

 In the general case then, <p M <pi $i' etc. in (52) will be 

 differentiable with respect to c\ c 2 . - ., and (53) et seq. will 

 not be valid. 



We have to consider the order of magnitude of the effect of 

 the variations of Ci c 2 . . . . upon the values of the quantities 



i* Midi*. 



In the first place, we note that variations in c 2 c 2 . . . . 



