"Unfortunately the colloidal silver and amine product put this formula out of standard home developer mix capabilities, although somebody may be able to suggest a relatively straightforward method of preparing the required amount of colloidal silver from a silver nitrate solution."

Here's a nice, vintage report on colloidal silver and it's preparation by Carey Lea himself:
http://books.google.com/books?id=K5M...lver#PPA337,M1

And another one from the same era with more details:
http://books.google.com/books?id=zZM...otropic+silver