[clark] viscosity OF ETHYL ETHER 59 



Figure 9 was drawn from data obtained with Tube 5 in which 

 the density of fiUing was so large that the tube was completely full 

 below the critical temperature. The liquid side only was studied. 

 In fact either side might be called the liquid side. One set of readings 

 was begun at about 160° and carried up to about 230°. The tempera- 

 ture was then lowered to near the critical temperature and then obser- 

 vations were made for temperatures near together, and carried on 

 until the curve ran into the curve for rising temperature. Then the 

 next day the temperature was pushed up to about 265° and lowered 

 again as before. 



II. Constant temperature results: — 



Experiments in 1912 while unreliable led to the conclusion that 

 the logarithmic decrement of the cylinder in the liquid side of the 

 tube decreased when the system was maintained at a constant tempera- 

 ture near the critical temperature and that the decrement for the 

 vapour side at first increased and then decreased. While these results 

 are unreliable on account of the method employed, it should be 

 noted that the conclusions are substantiated by the later work. 



