Can I Create a Dictionary of Generic Types?

I'd like to create a Dictionary object, with string Keys, holding values which are of a generic type. I imagine that it would look something like this:

Dictionary<string, List<T>> d = new Dictionary<string, List<T>>();  

And enable me to add the following:

d.Add("Numbers", new List<int>());
d.Add("Letters", new List<string>());

I know that I can do it for a list of strings, for example, using this syntax:

Dictionary<string, List<string>> d = new Dictionary<string, List<string>>();
d.Add("Key", new List<string>());

but I'd like to do it for a generic list if possible...

2 questions then:

1. Is it possible?
2. What's the syntax?