134 Analyses of Books. ' [Fkb 



of December, the variation on the 19th is rejected, on account of 

 its being unusually great. 



Jan. 10, 1815. — The needles vibrated between three and four 

 minutes ; and in the night the wind blew very hard, with rain, 

 from the west. 



Jan. 1 1. — At the morning observation the needles vibrated three 

 and four minutes. The wind still blew very hard, and continued 

 durins; the day. At noon the vibration of the needles was seven 

 minutes. 



„ . . ,, < Between noon of the 1st Dec. > n.mn ■ i 

 Rain fallen •< v> , r .i, i . t f 2'590 inches. 



I Between noon of the 1st Jan. \ 



Article XII. 

 Analyses ok Books. 



Memoirs of the IVernerian Natural History Society, Vol. IT. 

 Parti. For the Years 1811, 1812, 1813. Edinburgh, 1814. 



The Wernerian Natural History Society was founded in Edin- 

 burgh, in 1808, for the purpose of cultivating all the different 

 branches of natural history ; though, from the name given to it, 

 we are led to suppose that geognosy occupied the chief place, at 

 least in the opinion of the original founders ; as that name is de- 

 rived from Werner, the celebrated founder of that important 

 science. We had no opportunity of noticing the first volume of 

 Memoirs published by this Society, as it made its appearance before 

 the commencement of the Annals of Philosophy. The present 

 volume contains 20 papers, which we shall notice in their order. 



1. Outlines of the Mineralogy of the Ochil Hills. By Charles 

 Mackenzie, Esq. — Tliis paper having been already published in 

 the Annals of Philosophy, vol. iii. p. 116, we shall satisfy our- 

 selves with a very short account of it here. The Ochils are a 

 beautiful chain of hills, lying chiefly in Perthshire in Scotland, 

 and dividing Strathern from the river district of the Forth. Thei^e 

 mountains are all clothed with verdure, and many of them culti- 

 vated to the very top ; lience the rocks of which tliey consist are 

 seldom exposed, and the task of ascertaining their structure is 

 attended with almost insurmountable difficulties. It is not sur- 

 prising, therefore, that Mr. Mackenzie was unable to determine 

 exactly the relative position of the different rocks, and consequently 

 the class of formations to which they belong. For my own part, 

 1 consider the Ociiils as very like the Pcnthmds in their structure, 

 and think that both consisi of a series of rocks, not exactly similar 

 to any that Werner has described as constituting either the floetz or 

 the floetz trap; though, the lowest beds excepted, tlicy seem 

 more connected with the latter than the former. 1 suspect that a 



