Dr Davy on detached Bocks in Barbadoes, ^c. 105 



the uniform surfaces of rich sugar-cane cultivation by which 

 they are surrounded. In tvi^o or three instances they are 

 found on the sea-shore ; and there, no doubt owing to the 

 influence of the copious salt spray from the waves which 

 break against them, or near them, they are as remarkable 

 for their nakedness. 



On the sea-shore in the parish of St Joseph, near the out- 

 let of a rivulet called *' Joe's River," is one of these masses. 

 It may be about fifty or sixty feet high. I paced it, and 

 found its circumference at its base to be seventy-three of my 

 ordinary paces, or about one hundred and nine feet. When 

 the tide, which rises here from two to three feet in perpen- 

 dicular height, is high, it is surrounded by the sea ; and it 

 bears on its base seaward, diminishing from thence, land- 

 ward, the impress of the action of the waves, in the manner 

 in which it is worn away. On the land-side the effect is most 

 trifling ; but on the sea-side it is so considerable, as to form 

 there an overhanging roof, gradually heightening to a certain 

 line from the base, under which I could stand erect, and so 

 regularly worn, that were the rate of corrosion for a certain 

 period ascertained, the length of time it had been so acted on 

 by the waves might be determined probably with some pre- 

 cision. 



A single shrub grows on it, on its landward side, where 

 most sheltered from the sea spray. On its south-eastern 

 side, where, in some shallow cavities and fissures there is 

 an oozing of water (derived, no doubt, from rain falling on 

 the surface above), a mucor is there found, in part green, in 

 part blackish, where least exposed to the direct rays of the 

 sun, mixed whith a wite matter having the character of the 

 agaric mineral of mineralogists. 



This last mentioned substance is of a pure opaque white ; 

 when dry it is light, and easily broken and crumbly. Under 

 the microscope (prepared by being crushed on glass mixed 

 with a little water) its powder exhibits aggregate globular 

 masses, and particles nearly globular in form, varying from 

 about 3r(jVo of 3<n inch in diameter to 3^^^ ; somewhat resem- 

 bling, in appearance, certain compound organic globules, 

 frequently met with in the lungs after inflammation, and in 



