VOL. XXXIV.] PHILOSOPHICAL TRANSACTIONS. 187 



each other, and nearer respectively to the first two parhelia, which difference 

 M. Huygens attributes to the different altitude of the sun. 



Mr. W. thought he saw plainly at one time likewise, a small portion of a 

 secondary halo, as in the scheme at p. It seemed evidently to be an arch of a 

 circle concentrical with the halo, and tinged with the rainbow colours, whose 

 diameters might perhaps be to that of the halo, as 4 to 3 ; but as it appeared 

 but for a little time, he would not be positive about it. 



This face of the heavens continued, though with an interruption of some 

 parts now and then, till about a quarter after eleven, when Mr. W. left it, and 

 could not return till about twelve, at which time the sky was clouded over, 

 which had been before only hazy, a sure criterion of these appearance^ and 

 this phenomenon no longer visible. 



A Description of some rare Crystals lately discovered. By Dr. John Jame.s 

 Scheuchzer. N° 308, p. l60. From the Latin. 



On the high clifi^s of Grimsul there was a few years since discovered, in the 

 middle of a rock, a vein of crystals, which is since exhausted, very pure, and 

 the largest perhaps ever seen, the greater part of them amounting to about 6o 

 centners. The following is a series of the chief of those crystals. 



N° 1, is hexagonal, about 24- centners, is 2 feet 94- inches long, and 3 feet 

 74- inches round. 



N^S, weighed 13()lb. is 2 feet 3 inches long, 2 feet 9 inches round, with 

 some purple spots on the edge, but elsewhere very pure. 



N° 3, of 135 lb. is 2 feet 4 inches long, 3 feet 2 inches round, and is very 

 clear, except at the apex. 



N° 4, of 96 lb. is 2 feet long, and 2 feet 9 inches round. 



And so on, down to 10 lb. weight, of various qualities and proportions. 



Of a Stone taken out of a Horse, at Boston in New England, in the Year 1724. 

 By the Hon. Paul Dudley, F. R. S. N° 398, p. 261. 



The owner of the horse never observed any thing remarkable about him till 

 within a few days before he died, and then suspected that he might be troubled 

 with the gravel or stone, from the great pain the horse seemed to be in when 

 he staled or dunged, when he would groan and sweat prodigiously. After his 

 death, in the great paunch was found a stone of 54. lb. weight, almost as round 

 as a globe ; for it measured 1 7 inches round one way, and 1 7|- inches the other. 

 The grit was like a Newcastle grindstone; but it was worn smooth in the horse's 

 stomach, the colour somewhat like that of a nutmeg, but more of the ordinary 



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