122 



ART. 3. — B. KOTÔ : 



All three samples of ash derived from hypersthene-andesite, fell 

 near vents, and there exists general agreement among tliem. A 

 soluble portion of ash that fell on January 12 th at Kokubu Station 

 (p. 118) was tested by Mr. limori under the direction of Prof. Ikeda, 

 of the Tokyo Imperial University, with the following results : CaCl, 

 0.049%", NaCl 0.015%, sulphates trace. It may be remarked that 

 at the first phase the ashes contained clilorides while sulphates 

 occurred only in trace. NaCl is of primary volcanic origin, as the 

 writer took the sample before the inflow of tlio lava into the sea. 



The acidity^^ lessens with time as shov/n in the following, the 

 numbers given beinor reduced to the standard after Dr. Daikuhara : 



1) 15.75^",; of soluble silica. 



2) ' Report of the Krakatoa Committee of the Eoyal Society.' London, 1888. 



3) Daiknhara informed the writer, that the acidity exists in the soluble portion and is 

 mainly due to the presence of AlCl^. It is Chloraluminite with the composition ot AlCl^.&H^O, 

 and crystallizes in hrxagonal-rhombohedric. Wolff, ' Der Viilkanismus.' Bd. I. 



