‘o H. G. S- Broan: Handbuch einer Geschichte der Natur, 
188 The Botanical Gazette. [May, 
such names as Alex. von Humboldt and Sir J. D. Hooker stood be 
question I choose to reproduce my notes, not only because they are 
very interesting, but especially in order to find out if any one is able 
to give an explanation of the matter. Probably my article will be 
seen by some botanist who has an opportunity to investigate the sub a 
ject. 
1. A. von Humboldt makes the following remark,' giving an x 
count of his and Bonpland’s expedition to the hot springs at Trim — 
chera. “Die Ueppigkeit der Vegetation um das Becken iiberraschit 
uns. Mimosen mit -zartem, gefiedertem Laub, Clusien und Feigen 
baume haben ihre Wurzeln in den Boden eines Wasserstiicks getrie 
en, dessen Temperatur 85° betrug. Ihre Aeste stehen nur zwei, diel 
Zoll tiber dem Wasserspiegel. Obgleich das Laub der Mimosen — 
bestandig vom heissen Wasserdampf befeuchtet wird, ist €s doch sehr 
schén griin. Ein Arum mit holzigtem Stengel und pfeilférmiged 
Blattern wuchs sogar mitten in einer Lache von 70° Tempera 
bigs Pflanzenarten kommen anderswo in diesem Gebirge 
tioned. The centigrade scale was used. In his immortal Rélaton 
historique (11. 98) Humboldt tells the facts in the same way, a0 and Kir 
tend os 1874, 487-88) also states them. : 
2. Sir J. D, Hooker says? that a hot spring which he visited m ios 
has a maximum temperature of 190° F. (about go® C.), and yet! he 
found a Cyperus, and an Eleocharis(?) there, “having theit roots it 
ary! of 100°, and where they are probably exposed to 4 
eat.’ 
3. Sonnerat* found in a spring on Luzon Aspalatus and Vitex acs 
castus, having their roots in water of 8<° 
4. Stanton found‘ on the island of Amsterdam a spring, in te bot 
tom of which agg and Lycopodium were fixed, the tem mperature 
being 186° F. (36° al 
5. Sekondat se Tecmeile in water of 62° C., while Dunbat 
Hunter in springs in Louisiana noted Conferva as well as higher her plans 
Be: In or being peieticed by water of Sree C. x 
‘Reisen in d. Equin 
Hoo ooker's To Journ q Bsa aes ses os re jos a 
— Physique, 1774, p. 256; Voyage a la nouvelle rile Go 
‘Se Voit, Magazin fiir den neuesten Zustand der Naturkande, | Mig? 
