68 Scientific Proceedings, Royal Dublin Society. 



after explosion of the contained gas or steam, contract to the 

 surface, and present the dimple or ring-forms indicated. 



It is possible, if not probable, that under certain conditions 

 such globules should attain an extreme degree of thinness, and 

 thus, if the contained gas have sufficient buoyancy, be caused to 

 float in the air as minute balloons or bubbles. It is to be remarked 

 that these globules are thrown up by hot springs, and are so far to 

 a certain degree of the nature of the oolites, formed so frequently 

 by hot springs. What would be interesting to know is the nature 

 of the gases emitted, as also the temperature at which emitted at 

 present. 



"Wellington-, 21th July, 1887. 

 My dear Professor, 



Just a line, before the mail closes, to forward you with this 

 some specimens of ejecta from the hot springs at the Tarawara site, 

 handed to me by Sir James Hector for you. He says they are quite a 

 new departure, and to him novel. They are thrown up in immense 

 numbers, and burst on cooling inwards, as may be seen by some which 

 have not burst having depressions on them. 



He has had them analysed as follows : — 



Amorphous Sulphur, . 

 ,, Carbon, . 



„ Ash, 



,, "Water, 



,, Loss, 



Sir J. Hector says this is interesting, as being the first recorded 

 natural occurrence of sulphur in this form. 



Tours, William Ferguson. 



J. P. O'Reilly, Esq., 

 Royal College of Science, Dublin. 



