680 APPENDIX. 



etc., but seldom affording good specimens. Beyond these rocks, at the 

 N.W. extremity of the island, the cliffs are very high, consisting of trap, 

 often columnar, which continues for several miles ; but I have been told 

 that a stratified sandstone again appears for a short distance on the western 

 side, north of Duck Harbour, where I have not been ; but, from Duck 

 Harbour to the southern end of the island, I found the cliffs to consist of 

 trap, from 200 to 400 feet high (by estimate). 



" Concerning the age of these massive stratified rocks, I can only offer 

 the conjecture that they are Devonian from their appearance alone. 



'' Whether the red-sandstone of Inner Wood Island and conglomerate 

 of Gannet Rock are of the same age is very uncertain." 



On careful consideration of the above observations of Mr Verrill, in 

 connexion with the structure of the neighbouring coast, I think it probable 

 that the outer and older series above mentioned is either the equivalent 

 of the Acadian or St John series or of the liingston series, and that the 

 traps with the associated sandstones may be Devonian or Upper Silurian. 

 The colouring on the map represents one of these conjectures. 



(F.) — New Minerals from Nova Scotia. 



" Professor How announced in Silliman's Journal, Sept. 1857, the dis- 

 covery, in the great bed of gypsum quarried at Windsor, of the rare 

 boracic-acid mineral, Natro-horo-calcite, hitherto found only at Iquique 

 in Peru. Its formula, according to Professor How, is — 



Na 2 BO3 + 2 Ca 0, 3 BO3 + 15 HO. 



With respect to the geological conditions of its occurrence, Professor 

 How quotes from Professor Anderson of Glasgow the statement that, 

 in Pei'u, the mineral is found in a district supposed to be volcanic, and 

 embedded in the nitrate of soda deposits. He then remarks that, with 

 a very few exceptions, boracic acid is found " either in directly volcanic 

 regions, most abundantly as such, or as borax ; and a well-marked case 

 of actual sublimation of the acid from a volcano in the island of Vulcano, 

 near Sicily, has been studied by AVarrington ; or in smaller amount, in 

 minerals the products of recent or extinct volcanoes, as Humboldtite from 

 ejected blocks of Vesuvius, and zeolites and datholite from trap of Salisbury 

 Crags, New Jersey, and other places ; or in minerals of purely plutonic 

 or metamorphic rocks, as tourmaline, the rhodozite of lloze, and axinite — 

 the species which contain it at all being few in number. It may be noticed 

 also, that traces of this acid have lately been met with in the Kochbrunneu 

 of Wiesbaden and in the waters of Aachen." 



" If we may reason from the character of the majority of its situations, 

 we may almost consider the volcanic or at least igneous origin of boracic 

 acid so well established as to lead us, by its occuiTence in the gypsiferous 

 strata, to seek for some volcanic agency as the cause of their production. 

 Such an origin has, I iind, already been assigned to the gypsimi of Nova 

 Scotia by Dr Dawson. This formation has been shown to be a member 

 of the Lower Carboniferous series, and is assumed to have arisen from 

 the action of rivers of sulphuric acid more or less dilute, such as are known 



