To be brief, he took the materials, of which he made a compound, mixing them all and boiling them a good while until it seemed to him they had come to perfection.

He then asked for some vial to pour it into, and as there was not one in the inn, he decided on putting it into a tin oil-bottle or flask of which the host made him a free gift; and over the flask he repeated more than eighty paternosters and as many more ave-marias, salves, and credos, accompanying each word with a cross by way of benediction, at all which there were present Sancho, the innkeeper, and the cuadrillero; for the carrier was now peacefully engaged in attending to the comfort of his mules.
This being accomplished, he felt anxious to make trial himself, on the spot, of the virtue of this precious balsam, as he considered it, and so he drank near a quart of what could not be put into the flask and remained in the pigskin in which it had been boiled; but scarcely had he done drinking when he began to vomit in such a way that nothing was left in his stomach, and with the pangs and spasms of vomiting he broke into a profuse sweat, on account of which he bade them cover him up and leave him alone.

They did so, and he lay sleeping more than three hours, at the end of which he awoke and felt very great bodily relief and so much ease from his bruises that he thought himself quite cured, and verily believed he had hit upon the balsam of Fierabras; and that with this remedy he might thenceforward, without any fear, face any kind of destruction, battle, or combat, however perilous it might be.
Sancho Panza, who also regarded the amendment of his master as miraculous, begged him to give him what was left in the pigskin, which was no small quantity.

Don Quixote consented, and he, taking it with both hands, in good faith and with a better will, gulped down and drained off very little less than his master.

But the fact is, that the stomach of poor Sancho was of necessity not so delicate as that of his master, and so, before vomiting, he was seized with such gripings and retchings, and such sweats and faintness, that verily and truly be believed his last hour had come, and finding himself so racked and tormented he cursed the balsam and the thief that had given it to him.
Don Quixote seeing him in this state said, "It is my belief, Sancho, that this mischief comes of thy not being dubbed a knight, for I am persuaded this liquor cannot be good for those who are not so." "If your worship knew that," returned Sancho--"woe betide me and all my kindred!--why did you let me taste it ?" At this moment the draught took effect, and the poor squire began to discharge both ways at such a rate that the rush mat on which he had thrown himself and the canvas blanket he had covering him were fit for nothing afterwards.