Viscosity of a Solution of Saponine. 

 Table II. 



409 



r. 



MX/T. 





 1337 

 •2360 

 •3362 



Observed. 



Calculated. 



11-27 

 2037 

 29-36 



8-42 

 11-85 

 1907 

 3007 



The numbers are perhaps in as good agreement as could be 

 expected, if we remember that the theory on which they are 

 calculated is only approximate. If in the case of water we 

 neglect b, the value of a is 6' 9 2. 



After the above preliminary observations a careful series of 

 experiments was made in which the plate was gradually im- 

 mersed to a greater depth in water. 



The following are the results obtained : — 



Position of plate. 



Time of oscillation. 



Log. decrement. 



Upper edge of plate '7 mm. 1 

 above level of water J 



sec. 

 5-06 



5-10 

 5-10 

 511 



510 



5-12 

 511 

 513 

 5-17 

 5-18 

 5-20 

 5-20 

 520 

 5-20 



•0258 



•0259 

 •0260 

 •0262 



•0266 



•0272 

 •0272 

 •0285 

 •0298 

 •0329 

 •0366 

 •0415 

 0479 

 •0488 



•56 millim. above 



•28 „ „ 



•14 „ 

 Top of plate level with sur- "1 

 face of water J 



*1 below 



•2 „ 



•3 „ 



•4 „ 



•5 „ 



•7 , 



•9 „ 



1-3 „ 



1-7 „ 





In the above results, the level of the liquid is corrected for 

 the displacement of the liquid by the plate. 



Similar experiments were next made on the saponine solu- 

 tion ; but it was at once seen that the apparatus used in the 

 previous experiment with the water was quite unsuitable on 

 account of the great resistance offered by the surface. Cer- 



