BY THE REV. J. E. TENISON-WOODS, F.G.S., &C. 711 



vapours were continually ascending from its waters. Its margins 

 are precipitous on all sides, but higher on the south-east, where I 

 should say they rose between 80 and 90ft. high and almost vertical. 

 It was full of minei'al water, with a temperature which appeared 

 to be almost boiling. The sides of the lake were covered, in 

 1883, with crystals, but I saw nothing of the kind, and the water 

 was not steaming, but apparently still and cool. It would require 

 a very long cord to reach the water, at least longer than any I 

 possessed, so that I could not obtain specimens. Sefior CentenO' 

 was more fortunate ; he obtained some after a little difficulty. He 

 says that though of a deep green at a distance, in the bottle it 

 was of a very pale colour. The taste is more acid, bitter and 

 salt, than the water of the yellow lake, and gives a much moi'e 

 abundant precipitate on evaporation. The following is the result 

 of an analysis made by the official chemists at Madrid : — 



Analysis. Grammes. 



Sodium chloride 30-8588 



Potassium chloride ... ... ... 3 '47 16 



Iron chloride .. ... ... ... 9-6736 



Lime sulphate ... ... ... ... 0-4644 



Magnesium sulphate ... ... ... 3-0600 



Iron sulphate ... ... ... ... 1-6772 



Sodium phosphate ... ... ... 0-7620 



Silicic acid . ... ... ... 0-7400 



Free sulphui-ic acid ... ... ... 1-4888 



Free hydrochloric acid ... ... ... 7-8264 



60-0228 



This was, as in the former instance, the result of an analysis of 

 one litre of water. The proportion of solid matter is unusually 

 large, and the amount of chlorides quite extraordinary. 



Bed Crater. — Near to the green lake there is a circular crater, 

 about 400 ft. in diameter and 70 or 80 ft. deep, with almost 

 vertical walls. It is filled with volcanic detritus and scoriae of a 

 fiery red colour, and, during the rainy season, it is said to be filled 



