The. Active Volcano 0]i Tuna, Xeiu Hebrides. 83 



The phenomena connected witli the violent state might 

 be explained liy the fact that a lowering of the atmospheric 

 pressure would l)e followed by the rising of the column in 

 the vent, and so giving a larger (piantit}^ of lava to be 

 ejected. It would also be followed bj^ an increased quantity 

 of steam generated from the lava, which added to that 

 formed as before in the steam chamber, would cause the 

 eruptions to be much more rapid. This would be assisted 

 also by additional water supply in wet weather. 



The }jaroxysmal state may perhajjs be explained by the 

 sudden lowering of atmos])heric pressure for a great distance 

 along a volcanic fissure, the consequent formation of a large 

 quantity of steam, which h'nding its way to the place of 

 least resistance, would by its sudden exit cause a catas- 

 trophe. 



In conclusion I wish to state, that one of my chief objects 

 in submitting this paper to you is to direct attention and 

 inquiry towards this unique and little known volcano, and 

 also to the group in wliich this and other volcanoes exist ; 

 -and I have to express the hope that a S3^stematic and 

 thorouiih investigation of the manv interestin<»" scientific 

 features in the New Hebrides and surrounding islands, may 

 be a W(jrk in which the Royal Society of Victoria may see 

 its way to engage. 



X. — The Oceanic Langmaje'^ Seniitlc. 



By Rev. D. Macdonald, Fate, Havannah Harbour, 

 New Hebrides. 



