217 



The following Donations to the Library were announced : 

 The Quarterly Journal of the Chemical Society. No. 4. 8vo. — 



By the Society. 

 Railway Economy : An Exposition of the advantages of Locomo- 

 tion by Locomotive Carriages, instead of the present expensive 

 system of Steam Tugs. By Lewis Gordon, C. E. 8vo. — By 

 the Author. 

 Transactions of the Royal Scottish Society of Arts. Vol. III., 

 Parts 2 and 3. 8vo. — By the Society. 



Monday, htk February 1849. 



Sir T. MAKDOUGALL BRISBANE, Bart., President, 



in the Chair. 

 The following communications were read: — 

 1. On some peculiar Impressions on the Surface of certain 

 Strata of Greywacke Schist, at Goldielands, in Rox- 

 burghshire. By James Elliot. Communicated by David 

 Milne, Esq. 



After some prefatory remarks on the general character of the 

 greywacke formations in the south of Scotland, on their entire desti- 

 tution of organic remains, or even decided impressions, and on the 

 general prevalence of marks, produced apparently i)y shallow water, 

 a singular series of schistose strata is described, of little more than 

 two feet in thickness altogether, presenting everywhere peculiar fea- 

 tures. First, thei'e are two opposed surfaces, the one sprinkled over 

 with thin, short, raised streaks, and the other with small cylindrical 

 grains, all lying perfectly parallel to each other, and consisting of a 

 hard substance, differing from the material and colour of the grey- 

 wacke rocks. Next, there are a few seams of fine schist, and then 

 a surface, covered with minute, sharply-defined indentations, having 

 every one a lip turned up on one side, and sometimes clinging to 

 the lip, a small speck of the same hard brown substance, which ap- 

 pears on the two surfaces first mentioned. The lips are invariably 

 on the same side of the indentations, giving the surface the appear- 

 ance of a farrier's rasp ; and the uniform direction in which the lips 

 are thrown out from the indentations, is exactly parallel to the 

 'streaks and grains first described. At right angles to that direc- 

 tion are narrow undulating ridges, such as would be produced by a 



