Geological Society. 237 



From 4 to 3. 

 1. Faraday's researches on gold-leaf best illustrate this ; but I 

 hold that my explanation of them by masses of two degrees of 

 complexity only is sufficient without his conclusion (' Eesearches 

 in Chemistry/ p. 417), that they exist " of intermediate sizes or 

 proportions." 



From 3 to 2. 



1. Sulphur- vapour first gives a continuous spectrum at the blue 

 end ; on heating, this breaks up into a channelled space-spectrum. 



2. The new spectra of K and Na (more particularly referred to 

 in the third note) make their appearance after the continuous ab- 

 sorption in the blue and red vanishes. 



From 2 to 1. 



1. In many metalloids the spectra, without the jar, are chan- 

 nelled ; on throwing the jar into the circuit the line-spectrum is 

 produced, while the cooler exterior vapour gives a channelled ab- 

 sorption-spectrum. 



2. The new spectra of K and Na change into the line-spectrum 

 (with thick lines which thin subsequently) as the heat is continued. 



GEOLOGICAL SOCIETY. 

 [Continued from p. 153.] 



March 25th, 1874. — John Evans, Esq., F.R.S., President, 

 in the Chair. 



The following communications were read : — 



1. "On the Upper Coal-Formation of Eastern Nova Scotia and 

 Prince Edward Island, in its relation to the Permian." By Principal 

 Dawson, LL.D., F.E.S., F.G.S. 



The author described the Carboniferous district of Pictou County 

 as showing the whole thickness of the Carboniferous system ar- 

 ranged in three synclinals, the easternmost consisting of the Lower 

 series up to the Middle Coal-formation, and including all the known 

 workable Coal-measures in the district, — the second towards the 

 west of the middle and the lower part of the Upper Coal-formation, — 

 and the third showing in its centre the newest beds of the latter. 

 On the north the bounding anticlinal of the first depression brings 

 up the New-Glasgow Conglomerate, which contains boulders 3 feet 

 in diameter, often belonging to Lower Carboniferous rocks, and 

 represents the upper part of the Millstone-grit or the lower part of 

 the Middle Coal-formation. The anthor regards this as represent- 

 ing an immense bar or beach, which protected the swamps in which 

 the Pictou main coal was formed. 



The succession of the deposits above the Conglomerate was de- 

 scribed in some detail as seen in natural sections. Ihe Upper 

 Coal-formation, as shown in the section west of Carribou Harbour, 

 consists of: — 1. Red and grey shales and grey, red, and brown sand- 

 stones ; and 2. Shales, generally of a deep red colour, alternating 



