6L8 Prof. Rankine and Mr. Smith on the Viscosities of 

 Results : — 



Table II. — Sulphuretted Hydrogen. 



(The numbers in brackets indicate the number of observations 

 for which the figure quoted is the mean.) 



Temperature 

 (deg. C.;. 



Time of fall in seconds. 



Capillary 

 Correction 



Corrected 



Time 



09- 



Whole pellet. 



Two segments. 



(a) 17-65 

 {b) 100-4 



(8) 91-16 

 (8) 116-50 



(4) 9683 00553 

 (4) 122-93 0-0497 



86-12 

 11071 



Making the small corrections to the standard temperatures 

 17°-0 O. and 100°-0 C, we have 



£ 17 = 85*93 sec. and £ 10 o= 110*59 sec. 

 Therefore l^) =1-287, whence C = 331. 



\ tl7/H 2 8 



Also, at 17°-0 C, ^ = ^^- =0-6931. 



fair iZO'yb 



Correcting for slipping, we obtain 

 ^ =0*6921. 



Therefore, for sulphuretted hydrogen, 



Vu = 1-251 xlO" 4 C.G.S. units, 

 and ^00 = 1-610 x 10- 4 C.G.S. units. 



Cyanogen. 



The method of purifying this gas, and the manner in 

 which it is introduced into the viscometer, have been de- 

 scribed in a recent paper (loc. cit.) . Its purity was tested both 

 before introduction to and after removal from the viscometer. 

 The observations were made in the same order as in the case 

 of the sulphuretted hydrogen, since mercury also displays 

 somewhat abnormal variations of capillary phenomena when 

 in contact with cyanogen. 



