Just to clarify things: in your phrase "de la neige"; your "de" is not a preposition!
There are two different things you must not confuse:
a) the preposition "de", meaning "of" or "from" followed by the definite article "le, la, les", contracting to "du, de la, des" (and, of course, "de l' "
which generally translates as "of the" or "from the". Eg:
Il est accusé du meurtre de son voisin - "he is accused of the murder of his neighbour".
b) the partitive article "du, de la, des" (and "de l' "
which translates as "some". Eg:
Je voudrais du pain, du beurre et de la confiture - "I'd like some bread, some butter and some jam."