f 242 ) 



laria perhaps it is permitted to think of a later inversion of aragonite 

 into calcite but for the very new specimina <>l' Buccinum undatum 

 and Littorina littorea this explanation seems excluded. Possibly the 



form in which the lime carbonate is separated depends on external 

 influences and a species which builds as a rule an aragonite shell 

 may he able to separate calcite under abnormal circumstances (tempe- 

 rature, composition of the water . This appears to me the more 

 probable as we can precipitate artificially calcite or aragonite 

 according to the circumstances of temperature and composition of 

 the solution. If this should he true the composition of the shell is no 

 specific property. 



Geophysica. - - " Ear tkcur rent- Registration <it Batavia." (3 (1 com- 

 munication). By Dr. W. van Bemmelkn. 



In the preceding communication about my earthcurrent registration in 

 Java, I expected to he able before long to throw more light on the 

 question of the abnormal intensity of the current between Batavia 

 and Anjer (a place in the neighbouring residency of Bantam) 



The kind co-operation of the Superintendent of Government Rail- 

 ways, who allowed me the use of the railway telegraph lines during 

 night time, enabled me to realise my intention of measuring the 

 currents How ing between Batavia and some other places situated in 

 the residencies of Batavia and Bantam. 



In order to obtain an exaqt control over the new results, I registered 

 next to the currents (lowing through these wires, those between 

 Anjer and Batavia flowing through the direct telegraph line between 

 these towns, i.e. by means of the line formerly used by me. More- 

 over the N— S component of the magnetic force was recorded. 



By means of the railway telegraph-wires I obtained connection 

 with the following places: 



Laboean on the Westcoast of Java, 32 K.M. to theS.S.W. of Anjer. 



Serang 28 K.M. to the East of Anjer. 



Rangkas Betoeng 40 K.M. to the East of Laboean. 



Between Anjer, Serang, Rangkas Betoeng and Laboean there rises 

 a volcanic chain, the volcano Karang (1780 M.) being the culmi- 

 nating summit. 



Tangerang 21 K.M. to the West of Batavia. 



Bekassi 20 ,, „ „ E.S.E. „ 



Krawanu 54 ,, ., ,, E.S.E. ,, ,, 



