392 THE CANADIAN NATURALIST. [Oct. 



or " faulted." Similar dislocations in the solid crust of the earth 

 are generally supposed to have determined the spots where active 

 and extinct volcanoes have burst forth ; for several of these often 

 affect a linear arrangement, their position seeming to have been de- 

 termined by great lines of fissure. Another connecting link be- 

 tween the volcano and the hot-spring is recognizable in the great 

 abundance of hot-springs in regions where volcanic eruptions still 

 occur from time to time. It is also in the same districts that the 

 waters occasionally attain the boiling-temperature, while some of 

 the associated stufas emit steam considerably above the boiling- 

 point. But in proportion as we recede from the great centres of 

 igneous activity, we find the thermal waters decreasing in frequency 

 and in their average heat, while at the same time they are most con- 

 spicuous in those territories where,as in Central France or the Eifel in 

 Germany, there are cones and craters still so perfect in their form, 

 and streams of lava bearing such a relation to the depth and shape 

 of the existing valleys, as to indicate that the internal fires have 

 become dormant in comparatively recent t mes. If there be excep- 

 tions to this rule, it is where hot-springs are met with in parts of 

 the Alps and Pyrenees which have been violently convulsed by 

 modern earthquakes. 



To pursue still further our comparison between the hot-spring 

 and the volcano, we may regard the water of the spring as represent- 

 ing those vast clouds of aqueous vapor which are copiously evolved 

 for days, sometimes for weeks, in succession from craters during 

 an eruption. But we shall perhaps be asked whether, when we 

 contrast the work done by the two agents in question, there is not 

 a marked failure of analogy in one respect — namely a want, in the 

 case of the hot-spring, of power to raise from great depths in the 

 earth voluminous masses of solid matter corresponding to the heaps 

 of scoriae and streams of lava which the volcano pours out on the 

 surface. To one who urges such an objection it may be said that 

 the quantity of solid as well as gaseous matter transferred by springs 

 from the interior of the earth to its surfciceis far more considerable 

 than is commonly imagined. The thermal waters of Bath are far 

 from being conspicuous among European hot-springs for the quan- 

 tity of mineral matter contained in them in proportion to the water 

 which acts as a solvent ; yet Professor Ramsay has calculated that 

 if the sulphates of lime and of soda, and the chlorides of sodium 

 and magnesium, and the other mineral ingredients which they con- 

 tain, were solidified, they would form in one year a square column 



