198 EXPEDITION TO THE 



England, and to the rauchwacke and zechstein of Tliu- 

 ringen.* 



In offering these remarks to geologists, we have not 

 overlooked the very correct observation of one whose ex- 

 perience adds value to the advice which he gives to natu- 

 ralists ; indeed we have found the truth of Mr. D'Aubuis- 

 son's remark fully exemplified here. " Let us further 

 observe," says he, " that the influence of localities be- 

 comes more sensible as we draw nearer to modern epochas, 

 and we will be convinced of the difficulty of drawing cer- 

 tain conclusions as to the identity of two calcareous forma- 

 tions somewhat distant." If with this remark before us, 

 we are thought to have ventured too much in supposing a 

 connection between the formations of England and Ger- 

 many, and those west of the Alleghanies, let it be remem- 

 bered that we only offer this as a suggestion to the future 

 investigator of our western limestone, in order that he 

 may turn his attention to the subject with more favourable 

 opportunities of observation than those afforded us by a 

 transient visit through the country. We shall have occa- 

 sion to mention some further facts which we consider as 

 adding evidence to the opinion which we have advanced. 

 But there is another question which naturally arises; if, 

 as Mr. Freiesleben has described it, the zechstein pre- 

 sents specks of galena or sulphuret of lead ; if, as Mr. Co- 

 nybeare states, the galena is seen " occurring in strings in 

 the magnesian limestone of Nottingham and Durham ;" if 



• The reader is referred to the Outlines of the Geology of England 

 and Wales, by the Rev. W. D. Conybeare and Wm. Phillips, &c. Lon- 

 don, 1822, p. 300, & seq. Traite de Geognosie, par J. F. D'Aiibuisson de 

 Voisins, Paris, 1819. Vol.11, p. 336, 337, 343,353. J.C.Freiesleben's 

 Geognosliche Arbeiten, (Beytrag zur kentniss des kupferschieler-ge- 

 birgcs.) 



