226 PHILOSOPHICAL TRANSACTIONS. |^ANNO I675. 



bare, of seven or eight yards diameter, making a round path something more 

 than a foot broad, with green grass in the middle; the others like them, but of 

 several sizes, and encompassed with a circumference of grass, about the same 

 breadth, much fresher and greener than that in the middle. But my worthy 

 friend Mr. Walker, a man not only eminent for his skill in geometry, but in all 

 other accomplishments, gave me full satisfaction from his own experience. 

 Walking out one day among some mowing grass, in which he had been but a 

 little while before, after a great storm of thunder and lightning, which seemed 

 by the noise and flashes to have been very near him ; he presently observed a 

 circle, of about four or five yards diameter, the border of it about a foot 

 broad, newly burnt bare, as the colour and brittleness of the grass-roots plainly 

 testified. He knew not what to ascribe it to but the lightning. After the grass 

 was mowed, the next year it came up more fresh and green in the place burnt, 

 than in the middle, and at mowing time was much taller and ranker. 



As to the vomiting of strange worms, Mr. Lister observes, that a boy about 

 nine years of age, was afflicted with great pain in his stomach, and continual 

 vomitings. On giving him a powder containing a small quantity of mercurius 

 dulcis, he vomited up several strange worms, two of which were brought to me at 

 York, the one dead, the other alive, and which lived many days after it came to 

 my hands, and might have lived longer, but that I put it into spirit of wine, to 

 preserve it in its true shape. These worms were very caterpillars, with 14 legs, 

 viz. 6 small pointed, the 8 middle stumps, and the 2 hind claspers ; something 

 more than an inch long, and of the thickness of a duck's quill, thin haired, or 

 rather naked, with brown annuli, and a black head. The very same for kind 

 that I have often seen on plants, and no doubt these would in due time, if the 

 place had not hindered, have shrunk into chrysalids, and changed into moths, 

 as those mentioned by Mr. Jessop would have changed to beetles. 



Some Observations made in Scotland^ hy Sir George Mackenzie. Communicated ' 

 by Mr. James Gregory, N° 117, P- SqO. 



Of earths I have little to say : only one of our most ordinary soils for barley 

 in this country, is an earth dry and mixed with dung of cattle. In a place near 



where the agarics grew. It had existed for some years. These larger circles are seldom complete. 

 The large one just mentioned, was more than a semi-circle, but the phenomenon of fairy- rings is not 

 strictly limited to a circular figure. Where these rings are brown and almost bare, upon digging up 

 the soil to the depth of about 2 inches, the spawn of the fungus will be found of a greyish white , 

 colour; but where the grass has again grown green and rank, I never found any of the spawn existing. 

 A similar mode of growth takes place in some of the crustaceous lichens, particularly in the lichen 

 centrifiigus. Withering' s Arrangement of Brit, Plants, vol. 4, p. 222, 3d edition. 



