216 ART. 3. — B. KOTü : 



foundation of the volcano. They were burst and thrown out fi'om 

 the vent, commingled with other éjecta. That they are ancient 

 ultra- Sakura-jima andésite is proved by the presence of hornblende 

 and hiotite in fragments. The volcanics of above characters are 

 entirely wanting in the indigenous lavas that compose the body 

 of Sakura-jima. The infilhng of calcite in pumiceous space is 

 worthy of note, and it is not found in the trass with lava rind, 

 as calcite dissociates at 900°C. under normal pressure. The calcite 

 is at times vicariated by a brownish isotropic irregularly-split 

 ' opal '-hke substance, which greatly resembles imperfectly fused 

 feldspar grains in pottery. 



10) The so-called Sandstone. PL XXIII. Fig. 2. — Among the 

 western éjecta, the rock-collectors find grayish banded fragments 

 called sandstone in Sakura-jima. On the banding plane glimmer- 

 ing white flecks of biotite are seen looking like muscovite- sandstone. 

 The fi'acture at right-angles to the former shows wet-gray resinous 

 lustre. It is the pumiceous hypersthene trachyandesite bearing 

 hornblende and biotite {ho in Fig.), and constitutes the founda- 

 tion of southern Kyûshù and also the base of the insular volcano. 

 The two minerals are well seen in the photomicrograph, the 

 hornblende being darkened {ho) through the caustic action of recent 

 magma. 



Under the microscope, the resinous lustre is seen to be caused 

 by infilling of dirty amorphous silicate in the pumiceous hollows. 

 This glass- soaked rock was rent and thrown up like the preceding 

 trass to the surface, intermixed with polygenous projectiles. 



11) Ejected Blocks of Blotite-granite. PL XXIII. Fig. 1.— There 

 is a unique projectile among the éjecta collected by Kanai on the 

 margin of the main western crater, and this is a block of granite. 

 The rock in situ can only be found at a distance of Ibhn. 



