754. The Minimum Volume of Different Substances

Shabbos 18:2

The minimum volume of wine that would render one liable for transporting is a quarter of a reviis. (A reviis is somewhere between 3 and 4.5 ounces, so a quarter reviis is somewhere between 0.75 and 1.125 ounces.) If it has congealed, the volume is the size of an olive. The volume of milk from a kosher animal is one swallow; the volume of unkosher milk is enough to apply to one eye; of human milk and egg-white, enough to put in an ointment; of oil, enough to anoint a newborn baby’s little toe; of dew, enough to serve as the base ingredient of an eye ointment; of eye ointment, enough to mix with water (i.e. to be used for its intended purpose); of water, enough to wash the surface of a mortar (as in “mortar and pestle”); of honey, enough to apply to a wound. When it comes to blood, all other liquids, and all waste water, the minimum volume is a reviis.

Shabbos 18:3

The minimum volume of straw from grain that would render one liable for transporting is a cow's mouthful; of straw from pulse, a camel's mouthful. If one transfers straw from pulse specifically to feed it to a cow, he would be liable for transporting the volume of a cow's mouthful (which is smaller than the usual volume of a camel’s mouth). Eating with difficulty is still eating. The volume of ears of grain is a lamb's mouthful; of grass, a kid's mouthful. Leaves of garlic and onions are considered human food when they are fresh, so their volume is the size of a dried fig. When they are dry, they are animal food and their volume is a kid's mouthful. The various animal foods do not combine in order to render one liable for the more stringent volume but they do combine to render one liable for the more lenient volume. For example, let’s say that someone transports a combination of straw from grain and straw from pulse. If he transports a volume sufficient to fill a cow's mouth (the smaller, and therefore more stringent volume), he is not liable. If he transports a volume sufficient to fill a camel's mouth (the larger, more lenient volume), he is liable. This principle applies to all similar situations on Shabbos.