2,549. Checking a Lung

Hilchos Shechita 7:6

If a lung is found to have a spot that’s closed so that air doesn’t enter and it doesn’t inflate, it’s the same as if the lung was punctured and the animal’s a treifa. We check it by cutting off the part that doesn’t inflate when blown into. If fluid is found in it, the animal is permitted because it was the fluid that kept the air from entering. If fluid isn’t found in it, we put something like saliva, a straw, a feather, etc. over the piece of the lung and blow air into it. If the object moves, the animal is deemed kosher; if it doesn’t, the animal’s a treifa because air doesn’t enter.

Hilchos Shechita 7:7

Let’s say that a sound can be heard when a lung is inflated. If the place where the sound originates can be identified, saliva, a straw, etc. is placed over it. If it flaps, it’s clear that the lung is punctured and the animal’s a treifa. If the spot can’t be identified, the lung is submerged in lukewarm water and blown into. If the water bubbles, the animal’s a treifa. If the water doesn’t bubble, it’s obvious that only the lower membrane was punctured and the air moving between the two membranes is causing a sound when the lung is inflated.