Genesee county contains several valuable salines: but they are not extensively wrought, yielding only a few thousand bushels a year.
Sencca county enjoys fine salt springs in Wolcott and the neighbouring towns; but they are not produc tive at present.
The salt springs in the counties of Ontario, Niagara, Tompkins, and Oneida, have not been used thus far in the production of salt. They are individually of great worth to the proprietors and to the state, and will soon be made productive.
The strength of our salt springs is, upon an ave rage, greater than those in Europe, though it is a mat ter of no practical moment at the present clay. It should be remembered, however, that many European brine springs have been estimated too highly. It has been repeatedly said, for instance, that the brine springs of Barton and Northwich, in England, yield six ounces of salt to the pound of brine, or more than one-fourth part pure salt. Now, experiment proves, according to the minute investigations of the Bishop of Landaff, that this cannot be true; for allowing that sixteen ounces of water can hold six ounces of salt in solution, and no more, it follows that no brine spring can yield six ounces of salt from a pint of brine, be cause sixteen ounces of water with six ounces of salt would be a saturated brine of twenty-two ounces: therefore, if twenty-two ounces of brine yield six oun ces of salt, sixteen ounces of brine can yield only four and four-elevenths ounces of salt. So that the strong est brine can yield very little more than one-fourth part its weight of salt. Cheshire salt brine gives twenty two per cent.; in one remarkable case it gave twenty five per cent.; and once twenty-six per cent. of salt.
In Switzerland, from thirteen to fourteen per cent. is the usual strength of the salt brine springs. In France eleven per cent. is the average.
Most, or perhaps all our brine springs are original or primary sources. Sources are of two kinds: 1. Those which rise immediately over the bed im pregnating the water, or from a stratum immediately connected with it, though perhaps at some distance from the fossil.
2. Those which rise from a collection of salt water made in a stratum not immediately connected with the impregnating mineral.
It is not essential that a spring should rise immedi ately over a mineral charging its waters; because, after being impregnated, it may flow over an impervious stratum, as grauwacke, for example, and rise at a very considerable distance pure and valuable brine; it is still a primary source. But a body of water flowing over salt, or any other mineral, and oozing through different strata, until it reaches one that it cannot percolate, and'then it, follows it till, from some cause, (in what manner it matters not,) it rises to day, is a secondary source; because it neither rises over the mi neral, or any stratum immediately connected with it.
In mountainous countries, particularly, this is a sub ject of much importance, as the hopes of success are founded upon permanent sources, which the secondary never are, being liable to be diverted from their pre sent channels by slight obstacles. and to rise in other places. Some of the salines in Switzerland are worked on this principle of sources, and it often happens that a vein of water is intercepted, and leaves the brine spring dry.
At Halle, in Germany, and at many other places, mines are worked by cutting parallel galleries in the parent rock, and forming dykes, to turn water into them, where it remains until saturated. It is then drawn off and evaporated. In most cases judgment and experience are necessary in drawing water from salt pits, whether natural or artificial, where it reposes immediately on the salt. As the stratum of saturated water next the salt has an increased specific gravity, and will remain at the bottom, preventing the great volume of water from coming in contact with the mi neral to be saturated in its turn, it is necessary to keep the water in motion. Experience has proved the great utility of this expedient, which will saturate the water in a much more expeditious and effectual manner than by allowing it to remain at rest." 3. Rock Salt Mines.