Unus, one; solus, alone; totus, the whole; nullus, none; alter, the other; uter, whether of the two—make the genitive case singular in ius and the dative in i.
RIDDLES.
Q. In what case will a grain of barley joined to an adjective stand for the name of an animal?
A. In the dative case of unus—uni-corn.
Uni nimirum tibi rectè semper erunt res.
Hor. Sat. lib. ii. 2. 106.
Q. Why is the above verse like all nature?
A. Because it is an uni-verse.
The word alius, another, is declined like the above-named adjectives, except that it makes aliud, not alium, in the neuter singular.
The difference of unus from alius, say the London commentators, like that of a humming-top from a peg-top, consists of the ’um.