120 ART. 3.— B. KOTü : 



At the later declining phase it again increased in proportion as 

 the lava cooled and acquh^ed viscosity, thereby affording great 

 obstacles to outbursts which, when carried to effect, caused scatter- 

 ing and spreading of the rain of sand, by this time of juvenile 

 lava. The writer met with such rain on his second trip. The 

 sands and ashes are therefore of resurgent {lava ash) as well as 

 of juvenile {magma ash) origin, so that chemical analysis made of 

 them seems to be of restricted value, except for agricultural 

 chemists. If samples are gathered at special periods the results 

 attained are quite different. 



c) The LAPiLLi^^ (' karu-ishl ' or ' ga-ishi ') are fragments of 

 gray pumiceous lava of a size of 2 to 4 mm,, making up from 7 

 to d7% of the mass. The rest varies in size from 2 to 4 cm. 

 corresponding to the fine pebble in the above scale. They are no 

 doubt of juvenile origin formed during the first phase in the Strom- 

 bolian stage, and should be classed with the slag lapilli in contrast 

 to the crystal lapiUi."^ 



The writer is able to discriminate the eastern, Nabé-yama, 

 from the western, Yunohira, lapilli. The eastern are in appearance 

 whitish and fine vesicular with roundish outline. Microscopically, 

 we find idiomorphic olivine and hypersthene crystals, grouping 

 themselves in local patches, and magnetite crystals as well as 

 plagioclases are well crystalHzed in outline. Minute roundish air 

 pores (0.07 mm.) are enclosed in the highly strained colorless pure 

 glass. In short, the eastern lapuli are the froth of lava. 



The western lapilli, on the other hand, are dirty brown and 

 coarse with stretched air pores. They are characterized by the 



1) See the heading ' Recent Lapilli ' in Pétrographie Part. 



2) Idiomorphic anorthite crystals from Myake-jima and the Volcano Tarumai are well- 

 known examples. 



