54 Dr. Berger on the Isle of Man, 



ff Dun Earth. 



On the part of Dun How where the granite appears at the sur- 

 face, and in a natural excavation, but which I believe has been en- 

 larged by art, there is a brown sort of powder, said to be used by 

 the inhabitants for the cleaning of plate.* It feels rather soft to 

 the touch ; does not effervese with acids ; fuses per se, but not 

 readily, into a greyish enamel. 



ttt Marl. 



All over the curragh, and on the beach also at Kirk-inichael, a 

 substratum of marl several feet deep, underlies a light and sandy 

 soil. 



B.-Vodden marl. 



Calcareous marl of a light flesh colour, soft enough to be cut 

 with a spade, feels almost greasy to the touch, basis extremely fine, 

 texture dull and earthy ; no other discernible particles in the mass 

 but very small spangles of white mica ; adheres to the tongue strongly, 

 is soluble with a brisk effervescence in diluted muriatic acid, leaving 

 a considerable residue readily fusible into a slightly magnetic olive 

 enamel. 



Kirk- Mich a el-beach . 



Calcareous marl of a grey-reddish colour, not so soft as the pre- 

 ceding, owing to some sandy particles immersed in the basis ; leaves 

 in diluted muriatic acid a more abundant residue, not so easily 

 fusible ; the enamel of an olive-green colour. 



There is another variety of calcareous marl in the same place of 

 an ash-grey or of a dun colour. 



* Mr. Wood's account of the Isle of Man. 



