PROCEEDINGS OF SECTION B. 389 
The vegetation surrounding this flat was identical with that in 
the non-volcanic country, and terminated suddenly, but on the 
flat itself a few eucalypts were trying to exist. This is the most 
easterly point at which this tree was found in British New 
Guinea. 
Passing over this flat, which gave a hollow sound to the feet, 
showing that the crust was very thin, we climbed a low hill, and 
looked down upon a small lake shut in by hills, having a margin 
of dazzling whiteness, made by the crystallisation of salts, which 
tasted strongly of alum. At the foot of the hill was a spring of 
boiling water, which discharged into the lagoon. 
The low hills surrounding the lake were composed of sulphur 
and the white salt referred to above. The water of the lake, 
which was covered with wild fowl, was of a light yellow colour, 
and tepid, and the margin was surrounded by a thin crust, which 
gave way when trodden on, and let one of our party through into 
three feet of black slime. 
All round the base of the hills was a succession of holes full of 
boiling mud. Near the summit of one of the low hills we found 
a larger hole, which was throwing up liquid mud to the height 
of several feet with loud reports. (Photograph enclosed.) 
Further to the northward we found a similar lake and hot 
springs, and some of our party, who were obliged by the hostility 
of the natives to pass the night on the top of one of the sulphur 
hills, experienced much inconvenience from the fumes. At night 
the hills give out a bluish light. 
Sydney, 8th March, 1889. (Signed) B. H. THomson.” 
None of the specimens were in sufficient quantity to permit of 
a full analysis beimg made of their mineral constituents, the 
largest sample being contained in a so-called quart brandy bottle. 
The only quantitative determinations which could be con- 
veniently made were the total solids, fixed solids, loss on ignition, 
and chlorine and sulphuric acid. 
The loss on ignition includes any organic matter which may 
have been present, water of combination, volatile and decom- 
posable salts, together with some sulphur. 
There were four samples in all. 
SampLtE No. 1.—Labelled “ Seymour Bay, Ferguson Island, 
11th November, 1888. Boiling Water from Hot Spring.” 
This sample was contained in a sodawater bottle, and as one- 
half of it consisted of solid matter, it would be more correctly 
described as a mud. 
The sediment, or solid matter, was of a bluish-grey colour, and 
was found to contain a few diatom frustules and small crystals 
of selenite (calcium sulphate), and a good deal of sulphur. At 
