MODE VI. SERPENTINE. 



supposed, when only worn, to cure diseases of 

 the reins, or the lumbago*. This nephritic 

 stone is often found in flat pebbles on the shores 

 of the sacred island Hyona, among the Hebudes 

 of Scotland. It approaches to what is called 

 jad, the giada of the Italians, and is also found Jad. 

 in the island itself, adjacent to fine white mar- 

 ble. As jad however has never been yet ob- 

 served to constitute a rock, but, according to 

 the imperfect observations, has only been found 

 in rivers in schistose fragments, whence it would 

 seem only to form thin layers, it has not been 

 admitted into the present work. It must also 

 be observed, that the analyses hitherto given of 

 this substance are not satisfactory. The jad, 

 which forms the base of the composite rock 

 called the Corsican green, has been pronounced 

 by Werner to be a felsite, or compact felspar ; 

 and if the analysis of the younger Saussure be 

 trusted, it contains no magnesia. It may seem 

 to be nearly the same substance with the iconite 

 of the Chinese, only in a far higher state of in- 

 duration. This substance has also, by some 

 writers, been called lemanite, from the Lacus 

 Lemanus, or Leman Lake, now called the Lake 



* According to others, the stone, or gravel j in which sense it is 

 used by modern physicians. See Johnson. 



