Salt is likewise employed by iron founders in me tallic cements, and in rendering bar iron very mallea ble. It is used by whitesmiths and cutlers in case hardening, in tempering files, and some other edge tools; mixed with other substances for reducing me tallic ores, assaying minerals, and rendering metals fusible, by the refiners of silver, and to prevent the oxidizement of some metals. It is used to moderate the flame of combustible bodies; and is extensively employed by the philosophical and manufacturing chemist, and by the druggist for a variety of pharma ceutical purposes.
In horticulture, salt is much used, particularly in England, where its merits are better appreciated than with us. It prevents the depredations of insects on fruit trees, and when properly applied, protects them from the honey dew. Persons ambitious of having good cyder orchards are advised to dig a small trench a few yards from each tree, and place within it a few pounds of salt, which, by the rains, 8cc. is gradually conveyed to the roots, and produces the most desira ble effects.
In agriculture, I regret to say, salt has not met the attention it merits in this country. In after years, perhaps, when soil becomes more valuable, we too may be driven, as they now are in many parts of Eu rope, to seek means of rendering bad land productive, and literally leave no stone unturned that can tend to accomplish the object.
In Europe much has been said and written to prove and to disprove the utility of salt as a manure. With out entering at all into their ideas of the modus ope randi, we may judge from the effects of experiment.
I may say, however, that it has been supposed benefi cial in small quantities, by its tendency to promote putrefaction; and injurious in large proportion, be cause it then exerts its antiseptic powers. It has been supposed of benefit by destroying snails, grubs, and other animals in the ground.
It is observed by Dr. Darwin, that as it is a stimu lus which possesses no nourishment, but may excite the vegetable absorbent vessels into greater action than usual, it may, in a certain quantity, increase their growth, by taking up more nourishment in a given time, and performing their circulations and se cretions with greater energy.' In a greater quantity its stimulus may be so great as to act as an immedi ate poison on vegetables, and destroy the motions of the vessels by exhausting their irritability.
The reports of experimenters on the use of salt, as a manure, have been as different as the soils on which their trials were made; owing, in some measure, to causes which can never be foreseen or controlled, and on which agricultural experiment so generally de pends.
In soils of ferruginous sand, brought to a proper consistence by mud, or clay, or marl, salt has been found to exert effects superior to eight out of tell of the best manures. A quantity ground was pre pared, and divided into beds of forty yards in length, by one in breadth. The beds were then sowed and manured by the following substances, in the quanti ties mentioned: 1. No manure.
2. Salt, half a peck.
3. Lime, one bushel.
4. Soot, one peck.
5. Wood ashes, two pecks.
6. Saw dust, three bushels.
7. Malt dust, two pecks.
8. Peat, three bushels.
9. Decayed leaves, three bushels.
10. Fresh dung, three bushels.
11. Chandler's graves, 9lbs.
With the exception of chandler's graves, salt was decidedly the best of those used. On a trial of com pounds, the combination of salt and soot was the best. The substances were mixed in the following order, and the same quantity of each employed as when used singly: 1. Salt and lime.
2. Salt, lime, and sulphuric acid.
3. Salt, lime, and peat.
4. Salt, lime, and dung.
5. Salt, lime, gypsum, and peat, 6. Salt and soot.
7. Salt and wood ashes, 8. Salt and saw dust.
9. Salt and malt dust.
10. Salt and peat.
11. Salt, peat, and bone dust.
12. Salt and decayed leaves.
13. Salt and pearl ashes.
14. Salt and chandler's graves.
Perhaps this superiority may be accounted for by the quality of saline substances to attract moisture from the air; for those beds where salt had been used were visibly and palpably moister than the rest, even for weeks after the salt had been applied; and the ap pearance continued until rain fell, when, of course, the distinction ceased. In several instances the crop of the land failed altogether, except on the part where salt was applied.
It is to be remarked that these observations apply particularly to what are called ferruginous sandy soils; so that they are adapted, in a good measure, to some part of our salt formation; and much of the land lying between the Council Bluffs, and the Rocky Mountains, a band running parallel to the river Platte, is such, perhaps, as after ages may improve by the use of the salt abounding in the rivers in that region. It will be long before the population of that section of the union will be sufficiently numerous to make it necessary to think of it. It will be at a period when all our national resources are brought into action.