! ' 



GEUM. 



QBTSBBa 



OKITM, a genua of Plants belonging to the natund onler Kotare<r. 

 It has flat permanent calyx ; a limb in 10 acute deep segment*, 5 

 alternate one* much the smallest Petals 5, rounded, undivided, or 

 ilovcn, attached by their claws to the rim of the calyx opposite to its 

 mailer segment*, being about equal to the longer one*. The filaments 

 are numerous, awl-shaped from the rim of thu calyx, shorter than the 

 corolla. Carpel* superior, ovate, compressed, very numerous, in a 

 round head. Styles long, lateral, with a joint above the middle ; 

 lower part permanent, upper deciduous. Stigmas simple. Achenia 

 ovate, compressed, hairy, each with a long lateral tail, formed of the 

 enlarged hardened lower part of the style, terminating in a hook. 

 Koeeptacle cylindrical, dry, hairy, seated on the permanent reflexed 



i .:% \ 



Q. riralf, Wati-r-Avens, is found in meadows and woods throughout 

 Europe, and in Qreat Britain. It has a root somewhat woody, 

 blackish, creeping, and ruuniug deep into the ground ; astringent, 

 with the flavour of cloves. The herbage is hairy, and of a deep green. 

 The stem from 8 to 12 inches high, slightly paniclod, otherwise simple. 

 The radical leaves are stalked, their terminal lobe very large, rounded, 

 lobed, and sharply crenate. The stem-leaves are few, stalked, tern .te. 

 or y lobed ; stipules of the latter ovate, acute, cut, purplish. The 

 flowers are almost pendulous, singularly elegant, growing upright as 

 tin- fruit ripens. The calyx of a rich purplish-brown, erect, subse- 

 quently reflexed. The petiole is erect, cloven, and of a tawny brown. 

 It is considered to be a stomachic, and in said to be useful in diarrhira, 

 and is also employed in the United States in diseases of the bladder. 



6'. r6anm, Wood-Avens, is common in Great Britain and through- 

 out Kurope. The root consists of many stout brown fibres, astringent, 

 and in some degree aromatic ; it is said to give an agreeable flavour to 

 beer, and even to wine. The stem is 2 feet high, erect, round, rough, 

 and finely hairy ; branched at the upper part, bearing several flowers. 

 The radical leaves are on long stalks, interruptedly pinnate, somewhat 

 lyrate; the odd leaflet rounded, often deeply 3-lobed. Stem-leaves 

 ternate, stalked ; upper ones simple, 3-lobed, wedge-shaped ; all 

 variously notched and serrated, grass-green, veiny, and hairy. The 

 stipules of the stem-leaves very large, round, lobod, serrated, leafy. 

 The flowers terminal, solitary, stalked, commonly small, bright yellow, 

 erect. The calyx spreading, reflexed as tho fruit advances. Acln-nia 

 in an ovate head, numerous, downy, besides a few long coarse hairs 

 about the summit, each tipped with a ripe purplish deflexed awn 

 or tail, which is quite smooth, ending in a sharp small hook. 



'.'. Canatlen't, Chocolate-Hoot, Blood-Hoot, is valued in Prince 

 Edward's Island for its leaves and root, which are used as a mild tonic. 



(,'. inlri-meiliuin is found in damp woods in England. It has erect 

 or nodding flowers ; petals roundish, with a wedge-shaped claw ; calyx 

 of the fruit patent ; carpophore ; lower joint of the awn longer than 

 the hairy upper joint ; radical leaves interruptedly pinnate and lyrate ; 

 ^m-leavcs 3-lobed; stipules round, toothed; stem from 1 to 2 feet 

 high. The flowers are larger than those of (i. urbanum, less than 

 ile, yellow ; calyx purplish. The upper joint of the awn is 

 covered with long hairs, but with rather a long glabrous point. 



(Lindloy, flora Medica; Babington, Manual of Britith Botany.) 



i li'. VSKliS. This name is applied to a series of intermittent hot- 

 springs, situated in the south-western division of Iceland, where 

 Dearly one hundred of them are said to break out within a circle of 

 two miles. These springs are evidently connected with the volcanic 

 phenomena which so remarkably characterise the whole* district of 

 Iceland. A recent investigator of the eruptive phenomena of 

 Iceland thus describes its more prominent physical features : 



"The surface of Iceland slopes gradually from the coast towards 

 the centre, where the general level is about 2000 feet above the surface 

 of the sea. Ou this, as a pedestal, are planted the Jokull, or Icy 

 Mountains of thu region, which extend both ways in a north-easterly 

 direction. Along this chain the active volcanoes of the island ore 

 encountered, and in the same general direction the thermal springs 

 occur, thus suggesting a common origin for them and the volcanoes. 

 From the ridges and chasms which diverge from tho mountains 

 mighty masses of steam are observed to issue at intervals, hissing and 

 roaring, and where the escape takes place at the mouth of a cavern, 

 and the resonance of the cave lends its aid, the sound is like that of 

 tliuii'l' r. I/owcr down in the more pnrus strata wo huve smoking 

 mud pools, where a repulsive blue-black aluminous paste is boiled, 

 rising at times into huge bladders, which on bursting scatter tie ir 

 slimy spray to a height of 16 or 20 feet. From the base of the hills 

 upwards extend the glaciers, and on their shoulders are pi a 

 immense snow-fields which crown the summits. From the arches 

 and fissures of the glaciers vast mnssos of water issue, falling at times 

 in cascades over walls of ice, and spreading for miles and miles over 

 the country before they find definite outlet. Extensive morasses are 

 thus formed, which lend their comfortless monotony to the di m d 

 scene already before the traveller's eye. Intercepted by the cracks 

 and fissures of the land a portion of these waters is conducted to tho 

 hot rocks underneath ; here, meeting with the volcanic gases which 

 traverse these underground regions, both travel together, to issue at 

 the first convenient opportunity either as an eruption of steam or as 

 a boiling spring. 



" The origin of the water which feeds the springs is here hinted at 

 That origin is atmospheric. The summits of the Jokull arrest and 



mix the clouds, and thus cause an extraordinary deposition of 

 and rain. This snow and rain constitute the source from wh. 

 springs are fed. The nitrogen and ammonia which occur w 

 exception in every spring, exactly as we find them in ruin water, 

 furnish the proof of this; for the known deportment of these 

 substances preclude them from being regarded as real volcanic 

 products." 



Tho springs which feed the Geysers, and which are poured out 

 from them again boiling hot, probably take their rise i i Mount 

 tho summit of which is not more than 30 miles from the Geyser 

 district It is here that the rushing water is sometimes heanl in 

 chasms beneath the surface, and it has more than once hap, ! <i tli v 

 after earthquakes some of the boiling fountains have increased or 

 diminished, in violence ami volume, or entirely ceased, or that new 

 ones have made their appearance. 



The phenomena of the Geysers of Iceland have for a length of timo 

 arrested tin- attention o,f naturalists, and many explanations of them 

 have been given. No one has however so successfully investigated 

 the subject as Professor Bunsen, of Giessen. A summary of these 

 views, with experimental illustrations, were presented i 

 Institution by Professor Tyndall in June IS.'il!. After n -fen 

 the general eruptive phenomena of Iceland he described th< 

 Cieyser. " We have here," he snys, " a tube 10 feet wide and , 

 deep; it expands at ita summit into a basin, which t'rori north to 

 south measures 52 feet across, and iu the perpendicular din 

 60 feet The interior of tho tube and basin is coated with a beautiful 

 smooth plaster, so hard as to resist the blows of a hammer. The 

 first question that presents itself is, how was this wonderful tube 

 constructed ? How was this perfect plaster laid on ! A 

 at the constitution of the geyser water will perhaps furnish ;1. 

 surmise. In 1000 parts of the water the following constituents are 

 found : 



Silica 



Carbonate of Soda 

 Carbonate of Ammonia 

 Sulphate of Soda . 

 Sulphate of Potash . 

 Sulphate of Magnesia . 

 Chloride of Sodium . 

 Sulphide of Sodium 

 Carbonic acid 



0-1939 

 0-0083 

 0-1070 

 0-0478 

 0-0042 

 0-2521 

 0-0088 

 0-OJ57 



" The lining of the tube is silica, evidently derived from the water; 

 and hence the conjecture may arise that the water deposited tho 

 substance against the sides of the tube ami basin. But tho water 

 deposits no sediment, even when cooled down to tho free/in:- 

 It may be bottled up and kept for years as clear as cry .-t.d, ami 

 without the slightest precipitate. A specimen brought from Icclund 

 and analysed iu this institution was found perfectly free from 

 incut Further, an attempt to answer the question in this way 

 would imply that we took it for granted that the shaft was made by 

 some foreign agency, and that the spring merely lined it. A painting of 

 the Geyser, the property of Sir Henry Holland- liiin-ell a: 

 witness of these wonderful phenomena was cxhibite 1. The 

 painting, from a sketch taken on the spot, might be relied on. Wo 

 find here that the basin rests on the summit of a mound; this mound 

 is about 40 feet iu height, and a glance at it is suflicient to shew that 

 it has been deposited by the geyser. But in building the mound the 

 spring must also have formed the tube which perforates the mound ; 

 and thus we learn that the geyser is the architect of its own till re. 

 If we place a quantity of the geyser water in an evaporating lu-iu 

 the following takes place : In the centre the fluid de|>sitn nothing, 

 but at the edges where it is drawn up the sides of the basin by capillary 

 attraction, and thus subjected to a quick evaporation, we I'm,! 

 deposited ; round the edge we find a ring of silica thus laid on. ,.n,l 

 not until the evaporation is continued for a considerable timo do wo 

 find the slightest turbidity in tho central portions of thu water. 

 This experiment is the microscopic represeiitaut, if the term be 

 permit t-d. of nature's operations iu Iceland. Imagine the case ! a 

 simple thermal spring whose waters trickle over its side down a 

 gentle incline : the water thus exposed evaporates speedily, and silie.i 

 is deposited. This deposit gradually elevates ' > which (lie 



water passes, until finally the latter has to chouse another course; tie 

 same takes place here, the ground becomes elevated by the deposit as 

 before, and thu spring has to go forward thus it is compelled t 

 travel round and round, discharging its silica and deepening the shaft 

 iu which it dwells, until finally, in the course of centuries, the simple 

 spring has produced that wonderful apparatus which has so long 

 puzzled and astonished both the traveller and the philosopher. 



"Before an eruption the water fills both th tube and basin, 

 detonations arc heard at intervals, and after the detonation a violent 

 ebullition in the basin is observed; the column of water in the pipe 

 appears to be lifted up, thus forming a cuni* >! 

 of the basin and causing the water to lion . <T i- rim. |'i 

 nations are evidently due to the production of steam in the subter- 

 ranean depths, which, rising into the cooler water of the tub', 

 becomes condensed and produces explosions similar to those produce I 

 on a small scale when a flask of water U heated to boiling. Between 



