Note on the Spheroidal State. 85 



ture instantly comes into play. If, however, Mr. Stoney's theory 

 be true, then a drop of cool petroleum would be more easily and 

 longer sustained on a surface of warm petroleum, or vice versd, 

 than a drop taken from the mass of liquid below it, where only a 

 slight temperature difference is created. 



Two beakers were filled with petroleum from a common source, 

 one (a) at the temperature of the air, the other (b) at a tempera- 

 ture of 100° F. With a pipette some liquid was taken up from 

 A and a drop carefully deposited on its own surface, a globule was 

 formed, floated for a fraction of a second and then disappeared. 

 The same occurred with a drop from B placed upon B. A drop of 

 B was now removed and deposited on A, a large globule was easily 

 formed on the surface, floated about from 10 to 20 seconds and 

 then disappeared. A drop of A was now placed on B, the same 

 thing occurred, but the duration of the drop was not quite so 

 great, owing to the greater density of the cool drop tending to 

 sink it below the surface of the warm liquid, thus rupturing the 

 Crookes' layer and destroying the difference of temperature. 



There is no doubt or uncertainty whatever about this experi- 

 ment, and it shows that, if the ordinary explanation be correct 

 the second case, where B rests on B, should give the best result, 

 whereas the reverse is the case. Further, the experiment wherein 

 the best result is obtained, is such as best fulfils the condition of 

 Mr. Stoney's theory. 



The limit of formation of these spheroids, when the liquid is 

 uniformly dropped through a gradually increasing height, may be 

 employed to test the relative degrees of force which sustain the 

 globule, and careful experiments made by the author in this 

 direction still further corroborated the truth of Mr. Stoney's 

 views. 



U 



