42 A NATURALIST IN THE PACIFIC ch. hi 



Summary of the previous remarks on the hot springs of Vanua 

 Levu. 



(i) Hot springs have been recorded from 23 localities, but there 

 are probably many undiscovered or forgotten. 



(2) They are distributed over much of the island ; but have not 

 been observed in the Mbua or Western end and in the Undu ex- 

 tremity east of Lambasa and Lakemba. 



(3) They are confined to the areas of basic rocks and are not 

 known in the districts of dacites and other acid andesites or in those 

 of quartz-porphyry and trachyte. 



(4) They are always found at low elevations, never exceeding 

 300 feet. 



(5) Whilst more than half are situated along river and stream 

 courses, nearly all the remainder lie between the tide-marks. 



(6) In only two localities is the temperature at or near the 

 boiling-point. In one place it is 180 F., and in most of the other 

 springs it ranges between ioo° and 150 . 



(7) Siliceous sinter is formed where the temperature is over 150 . 



(8) As exemplified by the water of the Savu-savu springs the 

 proportion of salts in solution (8 per 1000) is constant over many 

 years ; whilst in this fact and in the relative amounts of each salt 

 there is a sharp distinction from the composition of sea-water. 



(9) The hot springs are older than the streams and rivers, along 

 which they are so frequently found. 



It would appear that they are largely supplied from the 

 " soakage " of the heavy rainfall in the mountains. 



