912. Measures of Weight

Eiruvin 1:11

When fresh wine (as opposed to cooked wine) is used for a shittuf, the requisite volume is two reviis per person; the same is true of beer. [A reviis is about 3.3 ounces, so two reviis is about 6.6 ounces.] The minimum volume of eggs is two and they may be used for a shittuf even when raw. Other volumes for a shittuf include: two pomegranates, one esrog, five nuts, five peaches, a litra of raw or cooked vegetables - though if the vegetables are only partially cooked, they are not in a condition normally eaten and may not be used for a shittuf – an uchla of spices, a kav of dates, a kav of dried figs, a maneh of crushed figs, a kav of apples, a handful of dodder (a plant), a handful of fresh beans and a litra of lichen. Beets are considered a vegetable and may be used to make an eiruv. Onion leaves may not be used for an eiruv unless they have already grown such that each leaf is as long as a spread-open hand; smaller than this, they are not considered food. All of these food are considered side dishes, which is why they have been assigned such measures; this list is not exhaustive. All foods combine to reach the minimum volume necessary to make a shittuf.

Eiruvin 1:12

The Rambam explains the measures of weight used in the preceding halacha:

A litra is equal to two full reviis; an uchla is half a reviis; a maneh is 100 dinar; a dinar is six maah; a maah is the weight of 16 barley corns; a sela is four dinar.  A reviis is a volume of water or wine equal to about 17.5 dinar. Therefore, a litra is equal to 35 dinar and an uchla is equal to 8.75 dinar.