I extracted this article from an old copy of the Transactions of the Gaelic Society. As there are a lot of Gaelic words in it I decided to make it a pdf file but have provided a wee bit of the introduction here for you to read.

INTRODUCTORY

The belief in incantations, like that in the evil eye, is world-wide and world-old. An incantation consists of a formula of words which is recited to bring about certain physical results to which the meaning of the words has some correspondence more or less direct. Thus, in Scotland, a sprain is cured in this way. A black woollen thread, with nine knots made upon it, is tied round the sprained limb, and while the thread is being put on, the operator mutters these words :—

The Lord rade
And the foal slade;
He lighted,
And he righted,
Set joint to joint,
Bone to bone,
And sinew to sinew,
Heal in the Holy Ghost’s name!

The principle underlying this spell is that of analogy—the recital of what the Lord did, with a call for, or expectation of, similar healing, is supposed to effect the healing process. But another aspect of the matter appears in the following English charm for cramp:—Stand firmly on the leg affected, and repeat with •appropriate gesture:—

The devil is tying a knot in my leg,
Matthew, Mark, Luke, and John, unloose it, I beg ;
Crosses three we make to ease us,
Two for the thieves, and one for Jesus.

Here is an evident reference to the action of demons, who, in certain stages of culture, are supposed to cause all manner of diseases. To expel this demon a more potent power had to be invoked, and this is done by a set formula, generally in metre. Here, then, the virtue of the “ spoken word” or magic formula lies in the fact of its being addressed to n. supposed living spirit or agent, capable of understanding and acting upon it; and this is the case in most charms, and ultimately this animistic notion may be the foundation of them all, whether analogical and symbolical, or directly invoking demon or god powers. Among savages the poetic and musical arts are used almost for this purpose alone. If one asks an Indian of the West for a love-song, he will tell him that a philtre is really much more efficacious. “ If you ask one of them,” says Kohl, who travelled among the Red Indians, “to sing you a simple innocent hymn, in praise of Nature, a spring or jovial hunting stave, he never gives you anything but a form of incantation, with which he says you will be able to call to you all the birds from the sky, and all the foxes and wolves from their caves and burrows.” The Maoris call incantations karukias, and employ them in actual life, such as for raising the wind by their means. The hero in their myths splits rocks before him with a karukia, just as the girls in the Kaffir and Bushman tales do; and by the same means he can assume any animal shape, be it bird or beast. The Finns are famed for their magic songs, but we shall quote only this blood-stopping formula:—“Listen, O blood, instead of flowing, instead of pouring forth thy warm stream. Stop, 0 blood, like a wall; stop, like a hedge; stop, like a reef in the sea; like a stiff sedge in the moss; like a boulder in the field; like a pine in the wood.” For the antiquity of these and like incantations we may appeal to ancient Chaldea, the land of Magic. Fortunately, a considerable body of incantations has been preserved in the cuneiform inscriptions, and of these one specimen must suffice :—

Painful fever, violent fever,
The fever which never leaves man,
Unremitting fever,
The lingering fever, malignant fever,
Spirit of the heavens, conjure it!
Spirit of the Earth conjure it!

Among the Aryan nations, ancient and modern, the belief in incantations has been strong. Indeed, a good case has been made put that some charms can be traced to the times of primitive Aryan unity. The sprain charm with which we began to exemplify the subject of incantations is very widely spread over Aryan ground.

You can download the pdf file here