Surf ace-tensions of Liquids in contact with Gases. 403 

 By (35) m 2 and e are the roots of 



r 2 -^i?+^ 2 =0 or £ 2 -48£+576 = 0, 



•so that m 2 = € = 24:. 

 Using (36) 



_e — m 2 — n 2 _ Q 

 1— n ' 



.and a, /3 are given as roots o£ 



f 2 -7» 1 f+m 2 = or ? 2 + 10?+24 = 

 by (37). 



Since a is the numerically smaller root, a=— 4, /3=— 6. 



The remaining constants are now given without any 

 .ambiguity by (38) to (41), viz.: y = n J -o>,-\- /3 + l = l, 



. __/?_.£ y — a — 1 __ 



— -=1, and 0= =2*4. 



The Series 



F(-3, -G, 2, 1) = 7 + 63 + 105 + 35 



leads to 11 = 10, c 2 = 504. The negative sign is required in 

 the ambiguity which occurs in the determination of Z\ since 

 yLt 3 <0. e and m are given by f 2 —46f+ 504 = and e must 

 lie taken =28, m 2 = 18 since e>m 2 . The equation lor a, /3 is 

 found to be f 2 +"<)£+ 18 = 0, so that a=— 3 and y3=— 6 in 

 accordance with the rule a < /3 . 



The effect of this note is to make the fitting in the paper 

 referred to determinate and unique. 



The author wishes to express his gratitude for much valuable 

 advice ami kindly encouragement received from Prof. Pearson 

 daring the preparation of the present paper. 



XLVIl. On the Surface-tensions of Liquids in contact with 

 different Gases. By Allan Ferguson, B.Sc. (Lond.), 

 Assistant-Lecturer in Physics in the University College of 

 North Wales, Bangor*. 



TI^HE question of the effect of the nature of the super- 



1 incumbent gas on the surface-tension of the liquid 



with which it is in contact does not appear to have been very 



exhaustively investigated. The only experiments with which 



* Communicated bv Prof. E. Taylor Jones. 



2D2 



