34 Dr W. Hibbert's Remarks on (he 



other presidencies might be cited. Now, the existence of 

 similar rocks in this neighbourhood I believe I have already 

 alluded to, as also the proximity of extinct volcanoes, and con- 

 sequently an intimation of a derangement of strata as an addi- 

 tional evidence is unnecessary ; and even should none of these 

 exist, there may be igneous rocks below the limestone, which, 

 as I before mentioned, exists in great quantity, and so im- 

 pregnates the various springs as to lead to the formation of 

 stalactites, resembling exactly those at Knaresborough, and 

 incrusting substances in a similar manner. Over and above 

 this, as an additional proof, it might perhaps not be out 

 of place to bring forward the origin of springs ; from the 

 circumstance of fresh-water occurring so near its source, the 

 ocean, where so very little humidity in the atmosphere is 

 known, shewing that filtration, capillary attraction, or some sub- 

 terraneous heat causing it to rise in vapour through fissures, 

 collect and issue in springs (which is the most probable and 

 certain), is the cause of this purification of the water. Strong 

 objections, and amongst these Dr Halley's stand prominent, 

 are, I am aware, started against these theories, such as no up- 

 ward filtration or current by capillary attraction, and so on ; 

 yet the latter, by collecting in cavities, might at least be suffi- 

 cient to produce intermitting springs. The last theory, how- 

 ever, upon the whole, is the most probable and likely, and only 

 allows of one objection, viz. the ceasing of springs on some oc- 

 casions in dry weather ; yet, I would not be understood to say 

 all are produced from the sea, but that many, very many, must, 

 and are to be accounted for in that way. Neither do I con- 

 ceive all cases equally apply to that of Dr Halley, that is, rain 

 falling on higher ground, filtrating and issuing at a lower level, 

 as if so, how account for springs and a permanent flow of such 

 on or near the summit of hills where neither rain nor clouds 

 are known, as in Upper Egypt ; or how, for the but slight 

 brackishness, if no effect from either filtration or internal heat, 

 the former of w hich, I am of opinion, must also have some effect. 

 This one might attempt to account for by saying, as is said in 

 dry weather, that the water collects in underground caverns, 

 and filtrating slowly, gets into the springs. But one naturally 

 asks, from whence the water to fill these caverns is derived ? not 



