56 HOW TO TIE FLIES. 



the "Materia Mediea" that it is akin to the 

 chamomile, and am therefore trying the virtue of 

 chamomile flowers, but up to the present time 

 I cannot say whether they would be of use or no. 



The last recipe with which I shall deal relates 

 to the last process through which a dry-fly goes 

 that which so markedly increases its powers of 

 staying above water, and which is commonly 

 referred to as the "oil tip." The ordinary 

 process, which was first made public in the 

 Fishing Gazette by the late Mr. Andrews, of 

 Guildford, is to soak the fly in paraffin oil, 

 or to brush the wings and hackle with the 

 same. I will not say that I have made any 

 improvement on this process, but from a priori 

 considerations, and from a few experiments which 

 I have made, I venture to think that such is 

 possible. Let me first, by way of preface, attempt 

 an explanation of the theory of the " oil tip/' 

 which may be new to many readers of this paper. 



Imprimis, it is necessary to understand that 

 there is a great difference between the molecular 

 structure of the particles at the surface of a fluid 

 and that of those beneath the surface. The 

 cohesive power of the latter is practically nil, 

 whereas that of the former is such as to cause the 

 surface of the liquid to assume all the properties 

 of an elastic skin. This will explain the well- 

 known fact that it is possible to cause a dry and 

 well polished needle to float on water. If the 

 needle be pushed through the skin, it will at once 

 sink to the bottom. Also, if the surface of the 

 needle be rough, the water will creep entirely over 

 it and the supporting skin beneath give way. The 

 needle being thus brought again beneath the 

 surface, will again sink. The case of the dry fly 

 not paraffined, and made of feathers which have 

 lost their natural oil, is similar to this latter. The 

 stretched elastic skin creeps over the feathers, and 



