S\6 FAIRY RINGS. 



church of the White Nuns of the order of St. A ugustin, said to be 

 found in the heart of a walnut-tree, on its being spit with lightning* 

 And it being usual in some countries to nail small images of our 

 Saviour on the cross, of Virgin-Marys, &c. to trees by the road-side, 

 in forests, and on commons ; it would be vo greater a miracle to 

 find any of these buried in the wood of the tree, than it was to find 

 the deer's horn so lodged. 



Sir Hans Sloane, in his noble museum, has a log of wood brought 

 by Mr. Cunningham from an island in the East-Indies, which, on 

 being split, exhibited these words in Po:tuguese, DA BOA ORA. 

 i. e. Det [Deus] bonam horam. 



[Editor. Phil. Trans. 1739, Vol. XLI. 



CHAPTER VIII. 



FAIRY RINGS. 



X his curious phenomenon has been differently accounted for. 

 The following is Mr. Nicholson's description and explanation : " the 

 appearance in the grass," says he, " commonly called Fairy Rings, is 

 well known. It consists either of a ring of grass of more luxuriant ve- 

 getation than the rest, or a kind of circular path in which the vege- 

 tation is more defective than elsewhere. It appears to be pretty 

 well ascertained, that the latter state precedes the former. Two 

 causes are assigned for this phenomenon : the one, which cannot be 

 controverted, is the running of a fungus ; the other, which has been 

 considered as an effusion of theory, is grounded on a supposition 

 that the explosion of lightning may produce effects of the same kind 

 on the ground, as Dr. Priestley's battery was found to produce on 

 the polished surface of a plate of metal, that is to say, a series of 

 concentric rings. Some observations, which I find in my common- 

 place book, appear to show that this last effect may, in certain cir- 

 cumstances, take place. 



" On Tuesday the 19th of June, 1781, a very powerful thunder- 



