54 ALUMINOUS CHALYBEATE SPRING IN I. OF WIGHT- 



Situation and " N. W* while that of Rockenend, not far distant, is S. E» 



natuial history << jjy g^ 



of tke spring. „,." . „ , . , , , ■, 



" Ihe elevation of this spot, as far as I could ascertam 



" it by the barometer, is one hundred and thirty feet above 

 " the lerel of the sea. Its distance from the shore may be 

 «« about one hundred and fifty yards. 



" The water is received into a basin formed in the rock 

 " for this purpose, and flows, as I was informed, at the 

 " rate of two or three hogsheads in a day. Its temperature 

 " I found to be 51°, that of the atmosphere being 48°; 

 " and it may be worth while to observe, that this tempera- 

 " ture corresponds with that of several springs of pure wa- 

 " ter which I have met with in the island. 



" The lower part of the cliff is rather encumbered with 

 * c masses of rock, or portions of soil, which have fallen 

 " from the upper strata. Immediately above these, the 

 * " spring issues from a bed of loose quartzose sandstone 

 '" containing oxide of iron. This sand, in which vestiges 

 " of vegetable matter are discoverable*, alternates with a 

 " purplish argillaceous slate of a fine grain, disposed in 

 " thin layers, with a few specks of silvery mica, interspersed 

 " through the mass, Black stains or impressions of vege- 

 " tables are seen on the natural joints of this rock. Above 

 " this lies a stratum, several fathoms in thickness, of a 

 '* blueish calcareous marl, with specks of mica, which has 

 *' an earthy and friable texture, and contains imbedded 

 " nodules or kidneys of Kulphuret of iron. Many of these 

 " nodules have undergone a partial decomposition, to which, 

 " no doubt, the existence of the principal ingredients of 

 •' the spring is to be ascribed. The upper strata of the 

 " cliff are composed of a calcareous freestone, alternating 

 " with a coarse shelly limestone, accompanied by nodules 

 u or layers of chert or flint. 



* On being sprinkled on a heated shovel, this sand scintillates as 

 if undergoing a partial combustion. When submitted to chemical 

 analysis, it yields a quantity of iron, bat no lime, nor aluruine, nor any 

 »>th<T earthy mutter soluble in an acid. Close to the spring this sand 

 contains some traces of sulphuric acid, but not at a distance from it : 

 it in evident therefore, that the sand rock is' not the medium through 

 which tke spring is impregnated, 



" As 



