254 Mr. Squires on Thomsonite. [Oct. 



b. The volcanic ; active, in Iceland, the Andes, &c. ; extinct, 

 in Auvergne, Banks of the Lower Rhine, &c. 



Their further consideration is not connected with my present 

 subject. 



In noticing in detail the second and third floetz series, I shall 

 confine myself in a great measure to those formations in Ger- 

 many, which came under the more immediate view of M. Freies- 

 leben, and are described by him ; my observations on which may 

 prove acceptable to the English geologist, by affording him an 

 opportunity of drawing for himself a parallel between them and 

 the British- The latter I shall here merely indicate, since they 

 form a field, of which we have hitherto received no full account, 

 and my own researches have been merely of a local character. 

 Their complete investigation, however, would probably bring to 

 light many instructive facts, and tend more fully to establish 

 their correspondence with the German. 



(To be continued.) 



Article II. 



On Thomsonite* a new Mineral Substance. 

 By P. Squires, Esq. 



(To the Editor of the Annals of Philosophy.) 



SIR, Norwich, Aitg.26, 1821. 



I beg to hand you a few particulars respecting a mineral 

 lately found in this neighbourhood by myself, which does not 

 seem to be described in any of the works on mineralogy with 

 which I am acquainted, and request, if convenient, you will give 

 it publicity in your pages. I am, Sir, with respect, 



Yours obediently, 



Paul Squires. 



The colour is snow-white, and sometimes yellowish-white, and 

 in the massive specimens passes into asparagus green. It 

 occurs crystallized in four-sided prisms, about an inch and a half 

 in length, terminated in flat irregular- sided pyramids, levelled at 



* In vol. xvi. p. 193, it will be seen that this name has been already given to a 

 mineral substance. It will be better, therefore, if Mr, Squires would designate th» 

 mineral found by him by some other term.— Ed. 



