432 Geographitdl Collections. 



water fonnation, (Montmartre ;) and are constantly crumbled down by variations 

 in heat and moisture. 



No house nor cottage of the most humble kind awaits the stranger on liis arri- 

 val at Hartfell, — a little rocky building, a fit residence for the hoary genius of the 

 place, points out the spring ; it is, indeed, a dangerous vicinity, and alterations 

 of situation in this erection, and even of the spring itself, may be expected with 

 the course of time. 



The mineral water, dripping at the time we visited it from the upper end of 

 the apartment, was observed to form a pond on the floor, which might be crossed 

 by means of stepping-stones. Its taste was slightly acidulated ; it sparked on 

 being poured into a glass ; and it deposits iron in its course. * The spring seems 

 hurtful to vegetation and to animal life. Mosses grow on its borders, but perish 

 in its waters, where every thing is more or less tinged with a dirty yellow. A 

 piece of written paper had been placed on the wall, and the ink-marks were en- 

 tirely eflfaced. A Trichomanes, which we picked up in the stream, had become 

 hard and friable ; the water did not, however, appear to aflTect an aquatic insect 

 which we put into it, though not another living thing was to be seen. The tempe- 

 rature of the air in the shade, on the 29th of July, was 25° cent. The tempera- 

 ture of the water in the well was 9°. The temperature of the air, at the head of 

 the ravine of Hartfell, remained the same ; while that of a well spring, the ther- 

 mometer being let down by a string did not indicate less than 10°. In another 

 running spring, surrounded by vegetation, near the summit of the mountain, it 

 descended in five minutes to 5° above 0, or freezing point. These hiUs were co- 

 vered with snow in the month of June- 

 It appears that the waters of Hartfell Spa increase in strength, or in the quan- 

 tity of mineral ingredients held in solution, when the stream is more abundant, 

 owing to parts of the rock, not constantly under their influence, being then acted 

 upon ; and it has been supposed that from this circumstance not^nly would a great 

 variation ensue in the quality of the waters, but that, with the progress of time, the 

 chemical constitution of the spring might be entirely different. When, however, we 

 •consider that the nature of a spring is not that of a running stream, excepting in 

 particular cases, as in limestone, and between strata of an opposite nature, but 

 is a percolation or filtering of water to form a stream issuing at the surface of the 

 earth, we do not see that such a supposition meets with any strong support ; 

 •while, on the contrary, it appears evident, from the friable slate constantly open- 

 ing new interstices, and every fragment exposing successive portions to the same 

 influence, that time will have little, if any sensible effect upon the constitution of 

 the spring, as long as it issues from the same bed. 



In the ravine upwards from the well, the mountain stream runs at different 

 angles, but sometimes in a line parallel to the direction of the laminae of the rock. 

 The rock becomes more and more fine in its slaty structure towards the summit : 

 in some beds it is dark-coloured, from the presence of carbonaceous matter ; in 

 some a grayish-white, with a silky lustre ; and in others it is of a brown-red cast, 

 from the presence of iron. It is apparently from one of the latter beds that Hart- 

 fell Spa takes its origin ; the colour is, however, entirely to be attributed to the 

 effects of decomposition. The stream has left a nearly isolated peak, of consi- 

 derable height, over one side of which it rushes in a small cataract. 



We may proceed to Birkhill, on the road to Selkirk, by the continuous valley 

 of Moffat Water, or from Hartfell Spa, traversing the mountain of that name, 

 and enjoying the extensive scenery of the plains of Dumfries-shire, the hills of 

 Cumberland, and the distant waters of the Solway Firth mingling in their out- 

 line with the gray horizon. Hartfell, on the eastern side, has an abrupt and 



* For the chemical analysis of these waters, we refer our readers to Dr. Gar- 

 net's Tour. Since iodine and bromine are supposed to exist in all mineral 

 springs, it would be interesting to know if they occur in mineral waters of the 

 transition formation. . - 



