424 Prof. J. J. Thomson and Mr. H. F. Newali. [Dec. 17, 



drop after falling into the liquid seemed to spread through it without 

 assuming any definite shape. We found when we used various 

 liquids that if the drops were let fall under similar circumstances, the 

 results depended only on the value of fxjp (the kinematic coefficient of 

 viscosity for the liquid). This is shown in the following table, where 

 the behaviour of the drop and the value of fxjp are given for several 

 liquids, which we have divided into classes. The viscosity coefficient 

 fx has been determined by Poiseuille's transpiration method ; that is, 

 from the time in which a constant quantity of liquid flows under 

 constant pressure through a fine capillary tube. To test the character 

 of the rings formed in the case of any particular liquid, drops of it are 

 let fall into a column of it from three different heights : 1st, such 

 that the drop just touches the surface of the liquid column at the 

 moment it detaches itself from the tube ; this height of fall is 

 denoted in the table by " fall = 0" ; 2nd, such that the tube is held 

 \ inch above the surface of the column ; 3rd, such that the tube is 

 held J inch above the surface. In describing the character of the 

 rings we have used terms which it will be well to define. " Splash " 

 denotes the irregular spread of the drop through the liquid column ; 

 it takes place with whirls and eddies irregularly, and is difficult to 

 represent, but the figure (5) would probably recall the appearance to 



Fig. 5. 



one who had seen the reality. " Uncertain" expresses that a ring or 

 a splash is formed, one as often as the other. " Blob " denotes the 

 appearance of a drop that does not break and spread through the 

 column, but remains within its boundary ; the figure (6) represents 



Fig. 6. 



the case. " DoubtfuV denotes that the drop tends to become a ring, 

 but that it is a question whether it ever leaves the state of a blob. 



