164 On the Composition of Oceanic 



of spheres. One of these spherical nodules was found, on being 

 broken, to contain a hard kernel of a mineral, giving a powder 

 of the colour of bichromate of potash, with a conchoidal fracture 

 and resinous lustre. Round this the spherical shells of man- 

 ganese were gathered, and could be easily broken off with the 

 fingers. Another nodule was noticed with the same yellow 

 resinous-looking substance in the centre, but it mixed with 

 the manganese forming part of the substance, and could not 

 be detached from the surrounding shells. It has a light wine- 

 yellow colour by transmitted light, and polarises light. Many 

 flat pieces were observed, with horizontal stratification and 

 botryoidal surface. Whether flat or spherical, the manganese 

 was put on in layers, separated by very fine sheets of the mud 

 of the locality. There was one nodule which had formed round 

 the fragment of another, and therefore older nodule, the 

 distinction between the two being well marked by the inclination 

 of the mud sheets of the kernel to those of the shell. There 

 were many where the clay or mud formed a large percentage 

 of the mass, either as interbedded layers or as pockets, and in 

 some of these pockets Foraminifera were to be seen. Amongst 

 the collection were two ear-bones of whales and a very fresh 

 shark's tooth, covered with the incrustation. The occasional 

 occurrence of icebergs at the surface was made probable by 

 the presence of two pieces of granite, the one with a very thin 

 covering, and the other with over one-eighth of an inch thickness 

 of manganese. On the fracture of one of the pieces, it was 

 evident that the manganese had filtered into the interior of 

 the stone, colouring the quartz a beautiful amethyst purple." 

 This haul was remarkable in many ways ; and not the least 

 in being the only important haul which we got in the vicinity 

 of continental land, and with no volcanic islands near. The 

 samples taken for analysis were 



I. The outer rind or shell of a spherical nodule, which was 

 detached without any trace of the kernel. It was 10 milli- 

 metres thick. 



II. A similar piece, detached from another spherical 

 nodule, but with traces of the kernel attached. It was also 

 10 millimetres thick. 



