Geological Society. 2 1 5 



hypothesis of a high central temperature ; and his object to get a 

 geological primum mobile in the nature of a vera causa, and to 

 trace its workings in a distinct and intelligible manner, so that in 

 future, instead of saying as heretofore, " Let heat from below invade 

 newly deposited strata, then they will expand, melt," &c, we shall 

 commence a step higher, and say, " Let strata be deposited, then, as 

 a necessary consequence, and according to known regular and cal- 

 culable laws,heat will gradually invade them from below and around j 

 and according to its due degree of intensity at any assigned time 

 will expand or melt them as the case may be," &c. The phenomena 

 of earthquakes, volcanic explosions, &c., may arise, but if all goes 

 on in quiet, the only consequences will be the obliteration of organic 

 remains and lines of stratification, and the formation of new combi- 

 nations of a chemical nature, &c. ; in a word, the production of me- 

 tamorphic or stratified primary rocks. 



In the formation of these therefore there is nothing casual ; all 

 strata once buried deep enough, and due time allowed, must assume 

 that state. None can escape j all records of former worlds must 

 ultimately perish. 



" An account of a Well at Beaumont Green in the County of He- 

 reford, fifteen miles from London, about a mile to the west of the 

 road to Ware ;" by J. Mitchell, LL.D., F.G.S., was last read. 



This well was dug in 1833, in the premises of Mr. Munt, a magi- 

 strate of the county, and the information respecting it obtained from 

 two gentlemen accustomed to collect evidence with the strictest 

 scrutiny. 



The strata passed through, were one foot vegetable mould, 15 feet 

 gravel, one loot sand with flints, 83 feet gravel clay, 15 feet blue 

 sand with black pebbles, 10 feet blue clay, \\ feet fine soft white 

 sand, or 126 J feet down to the chalk, which was penetrated for 40 

 feet when a spring was met with; but the digging continued 17 feet 

 lower to form a reservoir of water, and this was favoured by making 

 the excavation in the chalk of a bell shape, but above this the well 

 was 4£ feet in diameter. 



When the well was dug the weather was dry, but on this beco- 

 ming very wet the 15 feet stratum of blue sand and black pebbles be- 

 gan to emit foul air, by which one of the well-diggers was suffocated 

 in descending. A hawk flying over the well fell into it, and a similar 

 fate befell smaller birds, also wasps, bees and flies. On closing up 

 the mouth of the well, with the exception of an orifice an inch in dia- 

 meter, so powerful was the force of the issuing current of foul air 

 that it raised a weight of twelve ounces of lead. In fine weather 

 there was on the contrary a strong draft down into the well. 



Eight months afterwards the well was again entered when the 

 stratum of blue sand and black pebbles appeared forming into plum- 

 pudding stone. The well was rendered safe by bricking it down to 

 the chalk, applying a thick coating of compost over the whole. Dr. 

 Mitchell explains the phaenomena, by observing that the foul air was 

 no doubt sulphuretted hydrogen, produced by the decomposition of 

 water and iron pyrites. After long-continued rain j water penetrating 



