When a noncount noun refers to all of its type or to a concept in general, it is not marked with an article.

The noun represents kindness in general; it does not represent a specific type of kindness, such as the kindness he showed me after my mother’s death.

The noun rice represents rice in general. To refer to a specific type or serving of rice, the definite article is appropriate: The rice my husband served last night is the best I’ve ever tasted.

In most cases, when you use a count noun to represent a general category, make the noun plural. Do not use unmarked singular count nouns to represent whole categories.

Fountains is a count noun that represents fountains in general.

exception: In some cases, the can be used with singular count nouns to represent a class or specific category: The Chinese alligator is smaller than the American alligator. See also number 6 in 29b.