Have you ever wondered why, when you cry, you need to blow your nose? Today we find out the answer. The Talmud is currently discussing which kinds of bodily fluids are capable of transmitting ritual impurity in a person who has gonorrhea (called a zov). After declaring that nasal mucous transmits impurity, the next problem is do define what exactly is meant by nasal mucous (מי האף)?
נדה נה, ב
מאי מי האף ? אמר רב בנגררין דרך הפה לפי שאי אפשר למי האף בלא צחצוחי הרוק ור' יוחנן אמר אפילו בנגררין דרך החוטם אלמא קסבר מעיין הוא ורחמנא רבייה
What are these nasal fluids? Rav says: This is referring to fluids that are emitted via the mouth of a person. They are impure because it is impossible for the nasal fluids to flow through the mouth without containing traces of saliva, which are impure. And Rabbi Yochanan says: The baraita is referring even to fluids that are emitted via the nose. Evidently, Rabbi Yochanan maintains that nasal fluids are categorized as a flow of bodily fluids, and the Merciful One included it among the impure bodily fluids of a zav…”
Choose your ophthalmologist Carefully
Things get a little more complicated when the Talmud takes a surprising turn, citing a teaching that warns against having an idolator treating a Jew with an eye salve. This would cause blindness, since the Talmud thinks that the idolator would undoubtedly use a poison that would blind the Jewish patient.
If you were unlucky enough to find yourself in this predicament, there is a solution, at least according to Rav Chiyya bar Gurya: you can suck the poison from your eyes into your mouth and spit it out (יכול לגוררן ולהוציאן דרך הפה).
Rashi tries to explain the anatomical process:
דסבר אם נתן העובד כוכבים לתוכו סם המות יכול לגוררו ולהוציאו דרך פיו כדרך הרוקקין שמושכין מי האף בפיהם ע"י רוח נשימתם לגופן
He believes that…the poison can be removed by drawing it into the mouth. Just like someone who spits snorts the nasal mucous into their mouth by breathing in.
THE NASOLACRIMAL DUCT
There is indeed an anatomical connection between the eyes and the nose. It is called the nasolacrimal duct, and its job is to collect the tears from around the eyes and channel them down into the nose. Our tears are present all the time, and not just when we cry. They protect and lubricate the front of the eye and remove dust particles from its surface. But they need to be disposed of. Hence the nasolacrimal duct.
The nasolacrimal duct is surrounded by a boney canal created by the maxillary and lacrimal bones and opens into the inferior meatus of the nose. From Tillmann B. Atlas der Anatomie. Springer. Berlin 2005.
When tears are produced, they are directed from the surface of the eyes into the nasolacrimal duct by the coordinated contraction of the muscle surrounding the eye. From there, collagen fibers that surround the duct twist and wring out the duct, in the same way you would wring out a wet pair of socks by twisting them along their axis. Like this:
How the eyelids direct tears down the nose. The surrounding orbicularis muscle closes from the lateral side towards the nose, moving the tear film to nasolacrimal duct. From Weber, R. ed. Atlas of Lacrimal Surgery. Springer Berlin 2007, 5.
However, the function of the nasolacrimal duct is not under conscious control. This makes the suggestion of Rav Chiyya bar Gurya (via Rashi) that you could “snort your tears into your mouth” difficult to understand. Because you cannot. That aside, today’s passage reminds us of the existence and function of the nasolarcrimal duct, to which perhaps you will now pay greater attention.
Giving thanks for Human Anatomy
Hidden in the Bodleian Library in Oxford is a manuscript of a prayer book copied by a German Jew called Chaim in 1327. And in that prayer book (Opp. 758, p436b-438b) is a section called Birkat Ha-Eivarim, “Blessings over the Organs” that contains thirty-eight blessings.
Blessed are You our God for my ears and their hearing
Blessed are You our God for my eyes and their seeing
Blessed are You our God for my spleen and for my kidneys and their warmth
These blessings never made it into the standard prayers we say today, and were written when the human body was certainly more mysterious and less well understood than it is today. The nasolacrimal duct is an organ of wonder too, and perhaps it is included in this, another of the blessings found in Birkat Ha-Eivarim.
Blessed are You our God for my eyelids and their blinking.
NEXT TIME ON TALMUDOLOGY: BED BUGS
