86 Dr Lauder Lindsay on the Flora of Iceland. 
is a comparatively large stream, was hot, then warm, then 
tepid, for several hundred feet in its seaward course, also 
steaming more or less abundantly according to its tempera- 
ture; the mud and stones in the bed, and facing the banks, of 
the stream at its fountain-head, as well as the spring-deposits, 
were too hot to be handled with impunity. Add to these facts, 
that, on the occasion of my second visit to the springs, I found 
several washerwomen established on the banks of the Lau- 
gar, considerably below its fountain-head, where they found 
the water warm enough for washing purposes, their washing 
tubs steaming as satisfactorily as if they had been supplied 
with water boiled artificially —and that the said washerwomen 
found the water of the springs sufficiently hot for ‘‘ masking” 
their tea or coffee; and I think I am justified in inferring 
that the temperature of the springs must have been at least 
180°. The springs have deposited incrustations, which, like 
those of the Geysers, are essentially silicious, though they 
bear the closest resemblance to the stalagmitic (calcareous) 
deposits of many of our own so-called petrifying springs or 
streams, as that of Starley Burn, near Aberdour, Fife. The 
bed and banks of the stream in the vicinity of the springs 
consist essentially of parti-coloured muds, some of a deep 
blackish-green, others of a cobalt blue—some of an ochreous red 
colour; all having a sulphurous smell when fresh, and being 
very friable when cold. and dry. Chemical analyses of these 
deposits are given in my “ Contributions to the Natural His- 
tory of Volcanic Phenomena and Products in Ieeland” (Pro- 
ceedings of Royal Society of Edinburgh, Dec. 17, 1860), and 
in my account of “The Eruption in May 1860 of the 
Kotlugja Volcano, Iceland,” (Hdin. New Philosophical Jour- 
nal, Jan. 1861.) In the stream, from immediately below the 
springs, for a considerable distance downwards, and where the 
temperature of the water must have ranged from about 130° 
to 90°, grew luxuriantly a couple of Conferve. The one was 
of a deep greenish, the other of a yellow or rusty colour; both 
occurred in long tufts, and formed a slimy coating on the 
small gravel and sand, which constituted the bed of the stream, 
to which gravel, moreover, they adhered firmly. I collected 
and brought home with me specimens of both, but I had at 
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