I came upon publication and found this intriguing on gold for diseases and ailments. I know that it has been used for neurological purposes but never knew that it was good other things as well.
Since we're on the subject of metals, I know that platinum is used in chemotherapy, but I found other info on it. Platinum is one of the few substances that crosses over blood-brain-barrier.
In 1901 there were medical studies and practices using colloidals; silver, gold, platinum, etc. Here's a link to a Google Book - hope it pulls up okay.