Vol. 65.] 



LAHAT ' PIPE IN PERAK. 



Pig. 4. — Diagrammatic sketch of a specimen from the Laliat ' Pipe? 

 rather less than one third of the natural size. (See p. 388.) 



arsenopyrite 



arsenopyrite 



cassitente 



[This shows the distribution of the cassiterite, partly oxidized arsenopyrite, 

 quartz, and calcite.] 



The finest example of the second type is a deposit in a large cleft 

 in a limestone-hill, known as Jesophat's Valley. The following 

 points mark it as something distinct from the Lahat ' pipe ' : 



(1) The cassiterite occurs in rounded grains. 



(2) Rounded grains of quartz, tourmaline, and other minerals i 



(3) No trace of silicification of the wall has been found. 



abundant. 



A good example (also a pipe) of the first type has been worked 

 at Ayer Dangsang, by the Societe des Etains de Kinta, about half 

 a mile distant from the Lahat ' pipe.' It shows the following points 

 of difference : — 



(1) The abundance of fresh sulphides and the absence of iron-oxides. 



(2) A recognizable arrangement of the cassiterite-crystals in the calcite- 



matrix. 



The Ayer Dangsang and the Lahat ' pipes ' have points in common, 

 however, in the rarity of quartz and tourmaline. 



