Slice Types from An external Library

Hi,

I am working with an external Java library and would like to use objects from the library in my Ice application. I understand that in order to use these objects, I have to specify them within my Slice descriptor. How do I define these types as they are not part of ICE?

Say the "Organ" type is from the library is called "bodyparts.jar".

module Health {
    class Person {
        Organ heart;
        Organ kidney;    
    }
};