ORIGIN OF SULPHUR SPRINGS. 
155 
iron pyrites which exist in any one portion of these rocks, would certainly lead to the conclu¬ 
sion that the source of these impregnations is much deeper than that which is here assigned 
to them. 
But another strong objection to this theory of the origin of sulphureous springs is, that they 
very rarely contain sulphate of iron among their saline constituents. Now it is well known 
that the very agencies which would cause the evolution of sulphuretted hydrogen from iron 
pyrites, would also give rise to the formation of sulphate of iron. This being a soluble salt, 
we cannot understand why, if these waters are due to the decomposition of iron pyrites, they 
should not in every case contain the very substance, which is at least one of the results of this 
decomposition. 
Such are the objections to this view of the origin of these springs, even in those cases most 
favourable to its adoption; viz. where the springs emerge from strata which usually contain 
iron pyrites. But they are greatly increased in force, when the theory is proposed to be 
applied to those districts which are not thus characterized. We then have the additional 
difficulties presented, viz. the emergence of these springs from the oldest as well as the more 
recent rocks, as is .exhibited in the State of New-York, and the vast amount of sulphuretted 
hydrogen which they evolve ; an amount, which I think few would presume to refer to such 
an agency as that of the decomposition of iron pyrites, which seldom exists in any abundance 
in the older class of rocks. 
We cannot, therefore, I think, without great violence, refer these springs to a local origin, 
which is insufficient to explain their widely extended occurrence, while a more general ex¬ 
planation will be equally applicable to all the facts which have been observed. 
There are two general theories in regard to the origin of mineral springs. In both of them 
a general focus of action is recognized, which not only gives rise to what are usually con¬ 
sidered as volcanic phenomena, but to mineral springs of whatever character, whether thermal 
or not. In one case, however, these phenomena are supposed to result from the mechanical 
action of the solidified crust of the earth upon a fluid nucleus, the state of fluidity being the 
result and the evidence of intense heat. In the other theory, they are ascribed to chemical 
processes carried on within the earth; these processes, however, being the same in their 
character as those which give rise to volcanic eruptions. In other words, they are the direct 
products of the great volcanic focus existing in the interior of the globe; and that volcanic 
action, of which they form one of the manifestations, is to be ascribed to a chemical agency.* 
In the case of sulphureous springs, the substances necessary to their composition are water, 
sulphur, the alkaline and earthy bases, together with minute portions of carbonic acid and 
oxide of iron; the two last of which, however, may be independent of the general agency. 
All these bodies are known to be the products of active volcanoes — a circumstance of great 
importance in the discussion of this subject. This theory also receives confirmation from all 
the other facts which have been stated in regard to these springs, viz : 
* On these general views, I would refer to a valuable paper, “ On the Probable Origin of Mineral Springs,” by C. E. Stifft, 
formerly Mining Engineer to the Duke of Nassau. Edinburgh New Philosophical Journal, XII. 290. — And also to an article “ On 
the Mineral Springs of Iceland,” by C. Krug Von Nidda ; republished in the same work, Vol. XXII. 90. 
