PAIRY-RINGS. ^ 



That falry-rlogs fliould be produced by the excrements of Experiment 

 horfes, may be illuftrated by a very fimple faft, which It is in TuSate'the L 

 the power of every perfon to obferve. If you let fall fome duftions. 

 oil upon a marble (lab, or fome other liquid upon fome fub- 

 ftance that will imbibe it, you will fee it gradually fpread 

 round in a more or lefs regular form ; fometimes afiuming the 

 appearance of a patch, and frequently continuing to flow from 

 the center to the circumference, where it accumulates in a 

 much greater proportion than in the inner part of the circle, 

 taking thus the form of a ring. 



This accumulation of the fluid at the circumference may bo 

 eafily explained. As the fluid expands, the preflTure from the 

 center becomes gradually lefs, till at laft there is no fufficient 

 force t© overcome the reliftance oppofed by the dry parts of 

 the folid fubftance which has imbibed it : yet, in confequence 

 of the firft impulfe, the fluid will continue to flow from the 

 center through the fmall channels already opened, and will 

 thus accumulate in greater quantities at the boundaries where 

 its expanfive motion is flopped. 



The excrements of horfes, diluted by the rains and imbibed ApplIcatJon^ 

 in the foil, rauft have an effect fmiilar to that jufl defcribed. 

 This efFed mufl, befides, greatly depend upon the nature 

 of the foil and the facility with which it is pervaded by 

 the fluid ; hence the constant appearance of fairy-rings in 

 fome pafture-grounds, while none are ever to be found in 

 others. 



Should yon, Sir, confider thefe remarks, and the deduc- 

 tions which they have fuggefled to me, as likely to throw 

 fame light upon the caufe of fairy-ring?, you ara weleome to 

 make any ufe of them you may think proper, 



I am. Sir, 



Your obedient humble fervant, 



J. FLO R IAN- JOLLY. 



^ 2 Experiments 



