1868.] MATTHEW — PALAEOZOIC ROCKS. 391 



seen on the slopes and at the bottom of valleys of erosion, formed 

 between the hard conglomerates of Nos. 3 and 7. These softer 

 members also yield the elements of the fertile loamy soils, for 

 which the valleys of Kings County are famous. 



Along the margin of the great central coalfield, these " Lower 

 Coal-measures"* are much reduced in bulk; and volcanic 

 outbursts have left traces of their presence in that quarter, at 

 epochs corresponding to those marked by the spread of conglom- 

 erate beds (Nos. 3 and 7) among the Southern Hills. See 

 Prof. Bailey's Report, page 98. 



The following changes in that part of my article which relate 

 to this formation, will bring it into accord with the preceding 

 remarksf : — 



Page 431, line 11, for " which may represent" read " of later 

 origin than" 

 11 " 29, for "at or near" read " not far from". 



Sea-weeds in medicine. — The genus Laminaria consists 

 chiefly of large plants growing abundantly in deep water. They 

 are very rich in iodine, chlorine, sulphur, silica, lime, potash, and 

 soda. They are burnt in large quantities on the French shores 

 of the British Channel and Atlantic, and produce the best 

 raw soda from which iodine is afterwards extracted. There are 

 three species : — Laminaria digitata, L. saccharina, and L. bul- 

 losa ; and these almost exclusively yield the 70,000 kilogr. of 

 iodine annually brought into the market. There are also other 

 algae such as Fucus vesicidosus, F. nodosus, F. serratus, etc., 

 which generally yield bromine. The inhabitants of the Cordilleras 

 of the Andes were in the habit of using the decoctions of sea-weeds, 

 in cases of scrofula, wens, and lymphatic tendencies. These 

 liquids are, however, very unpalatable,- to avoid which M. Moride 

 proceeds as follows: — The plants are slightly rinsed in fresh 

 water, then dried and exposed to the sun, whereby they lose their 

 smell and taste of wrack ; after which they are pounded in a mor- 

 tar and macerated in strongly alcoholized water at a somewhat 

 high temperature. The iodized tincture thus obtained is 

 found useful in all affections for which iodine is prescribed. — Ex. 



* Dawson. — Synopsis of the Flora of the Carboniferous period in N~ova 

 Scotia. 



t Journal of Geological Society of London, Yol. xxi. 



