412 Chronicles of Science. [July, 



are printed in double columns, of which one is in the Portuguese 

 language, the other being a translation in French. 



We have pleasure in recording the publication of the text to the 

 volume of plates forming Part I. of M. Barrande's " Cephalopodes 

 Siluriens de la Boheme," which we noticed in our Chronicle in 

 No. IX. 



In the ' Annales des Mines' (vol. x.) is a welcome note on the 

 " Geology of the North of Madagascar," by M. E. GuiUemin, from 

 which we learn the existence of a coal-bearing series of deposits on 

 the north-west coast belonging to the Carboniferous formation, and 

 probably to the Mountain-hmestone ; but it appears that the beds of 

 coal seen by the author are of inconsiderable thickness. 



In a report by Dr. Sterry Hunt and Mr. A. Michel, of the 

 Geological Survey of Canada, on the Gold-region of Hastings, Upper 

 Canada, the occurrence of gold in rocks of Laurentian age is proved 

 beyond a doubt. This discovery still further enlarges the list of 

 gold-bearing formations, but as we cannot find any expression of 

 opinion by the authors as to the geological period of the impregna- 

 tion, this the more scientific aspect of the question is left open.* 

 The gold has been found in " three different associations : first, in 

 the black carbonaceous matter ; second, in the reddish ochery (sic) 

 oxyd of iron, which is found in the same crevices as the latter ; and 

 third, in plates in the midst of crystalline ferriferous bitter-spar." 

 These relations are no doubt very singular, and are thus explained 

 by Dr. Sterry Hunt : the black matter, probably in the form of 

 bitumen, was " first introduced into the fissures, which were sub- 

 sequently filled with the ferruginous bitter-spar, whose deposition 

 was contemporaneous with that of the gold," and whose decompo- 

 sition no doubt yielded the ochreous oxide of iron. 



In the March number of the f Geological Magazine ' is a paper by 

 Mr. Bofe, giving some collateral evidence on the subject of escape 

 of fire-damp, derived from observation of the escape of gases from 

 wells (especially "blowing wells") during different conditions of 

 atmospheric pressure. His conclusion " that coal proprietors should 

 take especial notice of any considerable fall in the barometer, and at 

 such times force an extra ventilation," &c, is perfectly sound, but 

 already well known to managers of collieries. The real difficulty 

 seems to be, how to suddenly augment in any considerable degree 

 the quantity of pure air circulating in the mine. 



There is also a paper on the Arenig and Llandeilo groups, by 

 the late Mr. "Wyatt Edgell, in which that very promising geologist 

 has endeavoured to show that the Llandeilo Flags can be separated 

 naturally into two groups, which he proposes to call " Upper 

 Llandeilo" and " Lower Llandeilo" respectively, the Arenig group 



* For a resume of facts and opinions on this subject, see Quart. Journ. Science, 

 No, xiii., p. 116. 



