1815.] Royal, Llnncean, and Geological Societies, 143 



increases as the tide rises, and the flow continues till the tide sinks 

 more than 50 inches below the mouth of the well. During storms, 

 the water flows in waves, similar to the waves of the sea. Mr. 

 Milne accounts for the flowing of this singular well in this way: 

 the whole bay, he conceives, has a clay bottom. The water between 

 the rock and this clay can flow out nowhere except at the termina- 

 tion of the clay, which is under the sea. As the tide rises, the 

 obstruction to this mode of escape of the water will increase. 

 Hence less will make its way below the clay, and of course it will 

 rise and flow out at the top of the well. 



At the same meeting a paper by Dr. Brewster was read, on the 

 effect of pressure on transparent animal bodies, in causing them to 

 polarize light. His first experiment was with a film of calfs-foot 

 jelly. At first it produced no eflect upon light ; but as it became 

 more and more firm it depolarized the light, at first at the edges, and 

 at last throughout. The same thing was the case with a film of 

 izinglass. When these films were subjected to pressure they 

 depolarized light at first, and exhibited those complimentary colours 

 which are peculiar to crystallized bodies. 



I^INN^AN SOCIETV. 



On Tuesday, the l7th of January, a paper by the Rev. Patrick 

 Keith, on the epidermis of plants, was read. He gave an historical 

 account of the ditferent opinions entertained by vegetable physio- 

 logists respecting the epidermis. He himself considers it as com- 

 posed of fibres rather than cells, an opinion adopted by some other 

 persons. He gave an account of the epidermis of saffron, in which 

 he found a peculiar structure. He observed pores likewise on the 

 veins of leaves, where hitherto it has been supposed that they do 

 not exist. 



GEOLOGICAL SOCIETY. 



In consequence of the great distance of the Editor from the 

 place of meeting of the Geological Society, it has not been in his 

 power for some time past to continue the regular details of the 

 interesting papers read at their meetings. He now resumes these 

 details from the time that they were interrupted. 



March 4, 1811, a memoir, entitled, Observations on the Hill of 

 Kinnoul, by Dr. Macculloch, V, Pr. G. S. was read. 



The hill of Kinnoul, in the vicinity of the town of Perth, rises 

 about COO feet above the plain of thcTay. It is nearly a mile in 

 length, and exhibits many abrupt faces in a state of constant ruin 

 and depredation. It consists principally of floetz trap, souietinies 

 in the btate of black basalt, sometimes of a brownish red colour, 

 but retaining the other characters of basalt; sometimes rendered 

 porpliyritie by the presence of numerous minute crystals of opake 

 felspar; sometimes porphyritie and an)ygdaloidal ; and sonictimcs 

 simply amygdaloidal, with a base of basalt, often ])asjing into 

 wacke. ^ 'J'hc concretions of the amygdaloid are green eartli or 

 chlojitc ill small grains, and varying in structure from compact tu 



