Use of the term "Resistance" in Physical Phenomena. 419 



The solution that I have used is composed of 



1 part by weight oleate of soda. 

 40 „ distilled water. 



These, when solution is complete, are well mixed with one 

 third the volume of glycerine and left for a week to settle in 

 stoppered bottles. The liquid is then syphoned off from the 

 impurities which have risen to the surface and clarified with 

 a few drops of ammonia. 



The thick wire rings and frames are made of tinned iron 

 wire 1 \ millim. in diameter, well cleaned with emery cloth. 



The thin wire rings may be made of any thin wire, but 

 aluminium about \ millim. in diameter does well. 



I have found it necessary to make a blowpipe with a trap as 

 shown in fig. 19 to catch condensed moisture, which is apt to 

 cause a failure if it mixes with the bubble. The diameter of 

 the mouth at a is 7 millim. For detaching small light bubbles 

 a pipe with a smaller mouth should be used. 



When both gas and air are used in any experiment and it 

 is necessary to regulate the proportions very carefully, it is 

 well to have a T-piece attached to the blowpipe, so that either 

 gas or air may be blown or stopped at pleasure. 



LII. On the Use of the term "Resistance" in the Description 

 of Physical Phenomena. By E. H. M. Bosanquet*. 



THE following observations were suggested by a remark 

 quoted by Prof. S. P. Thompson from Dr. Hopkinson, 

 at the meeting of the Physical Society on January 28, 1888. 

 The remark was to the effect that there is no such thing as 

 magnetic resistance, because the resistance of iron to mag- 

 netization is not constant under varying conditions. I wish 

 to bring before you the question, What is the fundamental 

 idea involved in the use of the term " resistance " in the 

 description of physical phenomena ? 



If we apply force to produce any change, say to extend an 

 extensible body, or compress a compressible one. the body" is 

 said to offer resistance to the force. If we have a second 

 body which requires a greater force than the first to produce 

 the same change, we say that the second body offers a greater 

 resistance than the first. Consequently resistance increases 

 with the force employed to produce a given change. 



Again, if in the second body the same force produces a 

 greater change than in the first, the resistance of the second 



* Communicated by the Author. 



