206 Proceedings of the Boyal Society of Edinburgh, 



The author proceeded to state, that, in consequence of the obser- 

 yations he had made as to the solubility of fluoride of calcium in 

 water, he had been led to look for that body in natural waters, and 

 had found it in one of the wells of Edinburgh, namely, in that sup- 

 plying the brewery of Mr Campbell in the Cowgate, behind Minto 

 House. At the same time, he stated that preceding observers had 

 already found it in other waters. He believed, however, that he 

 was the first to detect it in sea-water, where, by using the bittern or 

 mother-liquor of the salt-pans in which water from the Frith of Forth 

 is evaporated, he had found it present in most notable quantity. The 

 author referred to the presence of fluorine in sea- water, as adding an- 

 other link to the chain of observed analogies between that body and 

 chlorine, iodine, and bromine. 



Dr Wilson further stated, that he had confirmed the observations 

 of Will, as to the presence of fluorine in plants, and Berzelius' dis- 

 covery that fluorine exists in the secretion from the kidneys ; and 

 bad, in addition, detected fluorine in the blood and milk, in neither 

 of which has it been hitherto suspected to occur. The paper was 

 concluded by some observations on the presence of fluorine in fossils, 

 and its relations to animal life. 



Monday 20th April 1846. 

 The Right Rev. Bishop Terrot, Vice-President, in the Chair. 

 The following communications were read : — 



1. On the Constitution and Properties of Picoline, a new or- 



ganic base from Coal-Tar. By Dr T, Anderson. In- 

 serted in the present Number of the Edinburgh New 

 Philosophical Journal. 



2. Notice of Polished and Striated Rocks recently discovered 



on Arthur Seat, and in some other places near Edin- 

 burgh. By David Milne, Esq. 



Mr Milne stated, that, in the gully situated between Arthur Seat 

 and Sampson^s Ribs, a great extent of rock had been recently ex- 

 posed (by the removal of clay and other superficial deposits) which 

 was found to be smoothed as well as furrowed or scratched. 



The gully is about 30 feet wide, at the lowest level to which it 

 has been hollowed out, and at one part, both of its sides are composed 

 of these smoothed furrowed rocks ; but, in general, it is only on one 

 side, viz., that next to Arthur Seat, that rock exists. There, the 

 appearances of smoothing and rutting extend for about 80 yards. 



The gully runs about NW. and SE. by compass. The highest 

 point in it is near the north end. At both ends it is open and 

 sinks to a level with the adjoining level country. The gully is 



