In the fourth scene Desdemona tells Emilia that she does not know what is troubling Othello, but she firmly believes that he is incapable of jealousy (lines 27-29; another example of verbal irony). Othello appears, and Desdemona brings up the matter of rehiring Cassio. Othello responds by saying that his eyes are watering; and, so, he asks her for her handkerchief. When she offers Othello a plain handkerchief, he refuses it and asks instead for the special embroidered napkin that he had given her. Desdemona does not know where she had lost it, and she responds that she does not have it.
Othello then launches into a speech about
how the napkin has magical properties (lines 53-73). The napkin, according to Othello, was made by a sibyl (spiritualist or witch) who was 200 years old. An Egyptian sorceress gave the napkin to Othello’s father. The sorceress told him that as long as his wife kept possession of the napkin, he would love her fully and completely. But if his wife lost the napkin or gave it away, he would stop loving her and seek other women. Othello tells Desdemona that the same magic will work in regards to their relationship. If she loses the napkin, he will stop loving her.
There are two possible ways to regard the magic of the napkin. (1) Othello is making the story up to test his wife. Or, more likely, (2) Othello really believes what he says about the napkin. People during the Middle Ages and Renaissance were extremely superstitious and believed in witchcraft (even King James I believed in the magic of witches). And magical tales of the Near East (or Arabian countries) were well known. In such tales magical objects appear frequently: flying carpets, invisibility rings, Aladdin’s lamp with a genie inside. Most of the people sitting in the theater when this play was first performed most likely fully accepted and believed in the idea of a magical napkin.
Desdemona, of course, becomes frantic when she hears this news about the handkerchief. She does not know where she lost it, and she attempts to get Othello’s mind off of the napkin by talking about Cassio. This, of course, is the wrong topic to bring up. Othello becomes infuriated. He then swears and exits (line 95).
Desdemona still has absolutely no idea why Othello is so angry and acting so strangely. She incorrectly guesses that Othello has some problem with his work that “hath puddled his clear spirit” (139). She believes that some affair of business is troubling him. Emilia wonders whether jealousy has infected Othello (line 152). But Desdemona does not believe that such is possible.
The fourth scene ends with a conversation between Cassio and Bianca. Bianca is Cassio’s mistress. He has a relationship with her, but Cassio does not intend to marry her. Cassio shows Bianca the handkerchief that he found (which is the napkin that belongs to Desdemona). Cassio realizes that the owner of such a beautiful item will want it back. So, he asks Bianca to try and make a copy of it. And Bianca agrees. Thus, the audience now knows that Cassio has the napkin in his possession. And having it in his possession can only cause him trouble.