25 



40. An epicene envelope is represented by an epicene 

 primitive. But an epicene primitive does not represent an 

 epicene envelope, unless it gives a double value to the 

 arbiti'ary constant in the complete primitive. An epicene 

 primitive which does not give such double value is epicene 

 in form onl}^, and is in substance a particular primitive. 



41. A singular solution represents a singular envelope, 

 and a singular envelope is represented by a singular solu- 

 tion. A singular solution gives a double value to the 

 arbitrary constant in the complete primitive ; but a value 

 or relation which gives a double value to the arbitrary 

 constant in the complete primitive does not always represent 

 a solution, singular or other than singular. 



12, St. Stephen's Road, 



Bayswater, London, W., 



Decemher 9th, 1884. 



"Some novel phenomena of Chemical Action attending 

 the efflux from a capillary tube," by K S. Dale, B.A. 



The results obtained in the experiments I propose to 

 describe were the outcome of a desire to know what, if any 

 mechanical action took place where two solutions capable 

 of forming a precipitate, were slowly mixed. Next to find 

 the nature of such mechanical action, and latterly, if possible, 

 to measure it. I have made no attempt in the latter 

 direction, but propose describing a series of experiments 

 which have yielded some very novel effects. 



1. Solutions of Lead Acetate and Potassium Bichromate 

 were allowed to travel in opposite directions along a thread 

 placed in the field of a microscope. At the moment of 

 mixing very considerable disturbance took place, accom- 

 panied with a whirling motion. This method not offerino* 

 results which could be easily registered, it occurred to me 

 to cause one solution to flow into the other through a 

 capillary tube or syphon. The apparatus used was of the 



