A Session variable that is an array??

Is it possible to use a session variable as an array, and add items to the session variable array?
For example
dim ar as new Arraylist

Session("Stuff") = ar
Now that the Session("Stuff") is an arraylist, can I add an array to this session list?  
I want to do something like
 dim br as new array
Session("Stuff").Add(br)?
Of course this doesn't work.  Any ideas?

 
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