IN a large soup kettle, combine the beans, water, salt and baking soda. Bring to a boil, cover, and simmer for 5 minutes.
Remove from the heat, skim off any foam, re-cover and let stand for 2 hours.
(The beans can also be soaked overnight if you prefer)
Add the remaining ingredients except parsley and simmer, covered for about 1 1/2 to 2 hours.
Watch beans, for the cooking time will vary and the beans should not get mushy.
Remove the ham bone and dice any overly large pieces of ham and return to the soup.
Discard the bay leaves.
Add the parsley just before serving.
This soup freezes well too.