This artifact is said to resemble a gigantic sewing needle, about the size of a human hand, of solid gold, and a spool of silver thread of corresponding size, which never runs out.
The thread should be passed through the eye of the needle, and then tied off, as one would with a normal sewing needle. The needle should then be plunged into the patient's chest, forced through a fold in their skin and out again. It should be plunged in and out again and again, until the thread is used up. This will mend any ailment of the heart - melancholia, grief, or fear - so long as the thread holds.