276 



rei'tangles, it pi-oves I hat the circumference of the surface of tiie 

 li(|ui(i may not be too iriegiilai' and also that the linear dimensions 



D 



of this surface may not be too small with respect to f/— . 



a 



Tiien however for each of these rectangles E is proportional to 

 the breadth and to the ■ ,"' power of (he length. The total value of 

 E is found bj integrating over the whole surface, and it is easily 

 seen that this quantity for conform figures is proportional to the 

 Vs"^ power of the linear dimensions, of which this exponent Vi ^s 

 it were refers to the length and '/j ^^^ 'lie breadth. 



As all circles are conform it is proved by this that tiie evapora- 

 tion from a circular surface of a li(piid is proportional to the V>"' 

 power of the i-adius as is also found by Miss Thomas and Dr. 

 Ferguson, when the circumstances were in agreement with those 

 that are used at the theoretical treatment given above. 



The theory that is given here I have found conUruied by expe- 

 riments of the solving of crystals in a flowing liquid, which will 

 be treated in \\\)' dissertation. The quantity of the solved substance 

 proved to be proportional to the W"' power of the velocity of the 

 liquid, with the breadth and with the 7.'" power of the length. 



Institute for theoretical Physics. 

 Utrecht, December 1917. 



