72 Meetings of the Scientific Association of Great Britain. 
Mr. Kemp gave an account of a new mode of liquefying the 
gases, by which they may be obtained, much more easily, and in 
much larger quantities. Among the properties of the liquefied gas- 
es, he stated the independent bleaching power of chlorine, and of 
sulphuretted hydrogen, when liquid. 
Mr. Fox read a communication on the electro-magnetic condition 
of certain veins, and the continuation of the experiments was re- 
commended. 
GEOLOGY AND GEOGRAPHY. 
Chairman, Prof. Jameson. 
Sept. 9.—Slaty structure.—Dr. Boyle stated, that, from his own 
observations, all the characters of stratification usually ascribed to 
primary slates, do occur in granites also, and that the essential struc- 
tural characters of these slates are continued into the neighboring 
granites ; he thence inferred, that, there is no real structural distinc- 
tion between the granites and the primary slates.* 
This opinion was either opposed, or the difficulty was, to a degree 
modified, by different gentlemen present, and Prof. Sedgwick stated, 
that, he had adopted the same opinion as that of Dr. Boyle, after a 
visit to Cornwall, sixteen years ago, but that an investigation in North 
Wales and Cumberland, had considerably altered his views. 
Gradual elevation of parts of Sweden, &c.—Mr. Lyell, being 
invited, gave an oral statement of his observations in Scandinavia, as 
to the supposed change in the level of the Baltic. 
Celsius, more than one hundred years ago, contended, that the 
level both of the Baltic and of the main ocean, was undergoing a 
gradual depression, and he referred to the following proofs: 
1. Towns with sea ports, formerly, situated on the coast of the 
Gulf of Bothnia, are now far inland, and new tracts are becoming 
dry along the shores; to this, the inhabitants bore testimony. 
2. They also say, that various insulated rocks in the Gulf of 
Bothnia, and on other parts of the eastern shores of Sweden now 
rise higher above the sea, than formerly, as seen in their youth. 
3. Marks were cut in the fixed rocks on the shore, thirty years 
before, or more, to indicate the extreme altitude of the waves, when 
* In this country, there can be no question that granite is, in general, clearly 
distinguished from the primary slaty rocks, as is plainly seen in all quarries where 
these rocks are cloven; gneiss, mica slate, and the other slates cleave, easily, 
through their slaty structure, while granite shews no such disposition, but splits, as 
readily in one direction, asin another.— Ed. 
