Mineralogy andGeology, 383 



This is not a complete list of the grasses growing in this neighbourhood, 

 but the variety is sufficient for my purpose ; and taking into consideration 

 the small space in which they were found, it contains as many as a similar 

 extent of country in any other part of the kingdom will produce. Out of 

 the number, twenty-eight at least grow upon Bungay Common. — D. Stock. 

 Bungay y April. 



As the grasses enumerated by our correspondent include the greater 

 number of the most common species, we have figured them, in order to afford 

 our young readers an easy opportunity of acquiring their names. London 

 students have only to purchase a truss of hay, out of which they may pick 

 specimens of several of the species ; many, also, may be gathered in Ken- 

 sington Gardens, or in any of the^ lanes and meadows round the metro- 

 polis. — Cond. 



Art. IV. Mineralogy and Geology, 



Origin of Jet. — In the Cabinet of Mineralogy in Languedoc, M. Chap- 

 tal preserved several pieces of wood, whose external part is in the state of 

 jet, while the internal part still remains in the ligneous state ; so that the 

 transition from the vegetable to the mineral state maybe distinctly observed. 

 At Montpelier have been dug up, several cart-loads of trees converted into 

 jet, with their original forms so perfectly preserved, that the species of trees 

 thus bitumenised can often be determined. A specimen of jet from Vachery 

 can be distinctly recognised, as retaining the texture of the walnut tree ; and 

 the texture of the beech can be traced in the jet from Bosrup, in Scania. 

 The most singular instances, however, are those of a wooden pail and of a 

 wooden shovel, which M. Chaptal, whose authority is undoubted, affirms 

 to have been converted into pure jet. 



Age of Strata traced from their Organic Remains. — The relative age of 

 strata is often demonstrable, as in the instance of veins crossing and recross- 

 ing, which must as clearly have been formed after the strata which they 

 cross, as the trench of a drain must have been formed after the strata of 

 soil through which it passes. On a similar principle, it has been attempted to 

 prove that the schistose strata at CEningen have been formed within a recent 

 period, because they not only contain distinct remains of the indigenous 

 vegetables of the vicinity, but those of the walnut (Juglans regia). Now, 

 the walnut not being an indigenous tree, the history of its introduction 

 from Armenia into Italy, and thence into Germany, is known j and, conse- 

 quently, the chronology of it will pretty nearly determine the age of the 

 strata. — J. R. 



Consequences of continued Disintegration of Strata. — According to Hut- 

 tonian geologists (a class now diminishing no less rapidly than their rival 

 Wernerians), the changes of the earth are interminable, both as to past and 

 future. On Wernerian principles, we may say, I think, that the continual 

 disintegration of rocks, and the continual travelling of their debris to lower 

 levels, will at last reduce the globe to uniformity of level, such as some spe- 

 culators suppose it to have been before the deluge, or, at least, before the 

 fall of man. But Wernerians assert that some granites in Sweden have 

 retained Runic inscriptions for 2000 years, and that basaltic columns pre- 

 serve their angles well defined, in defiance of the influence of weathering ; 

 forgetting, however, that they cannot tell whether those Runic inscriptions 

 maintain their original depth of engraving, and that basaltic columns are 

 disintegrated by being rolled from their jointings, and, afterwards, commi- 

 nuted by attrition, &c. They say, also, that disintegration goes on in a 

 decreasing ratio, as the rock becomes sheltered by soil ; forgetting that this 



