I HAVE MY GRANDFATHERS old glass inkwells from the 1850s. These inkwells are filled about 90 percent with very small round lead shot about the size of 1/2 to 1 mm. One of the bottles is kept filled with ink about 2 mm above the lead shot. The other bottle is filled with Naphtha about 1 to 2 mm above the shot.
 
Here is the way it works. The lead shot serves three purposes in the inkwell, when you dip your pen into the ink you will feel your nib come in contact with the small lead balls and you will know that you have dipped the pen far enough; also when you dip your pen into the lead shot, it will serve to gently clean your metal nib as well. After you have finished writing with the ink, you can then dip your pen into the other bottle of shot filled with naphtha and the shot and naphtha serves to clean your pen nib.
 
In addition to all this, my father told me that the heavy lead shot will serve to make the bottle weigh a lot and not tip over. He went on to tell me that when you have an ink well with lead shot in it, the lead will partly dissolve in the ink giving it a more beautiful color and make it a lot darker and with a raised gloss; the ink will have a unique beauty all of its own. I have noticed that many people that still use pens will have large amounts of lead in the ink bottle.

YOU CAN PURCHASE lead shot at a gunsmith shop as they sell small lead shot for reloading shotgun shells. You may find that the shot is nickel plated, if that is the case it is okay to use nickel plated lead shot (99 percent of the shot is not nickel plated and it will not make any difference.)

The gunsmith here would not sell me just a few spoons full, I had to purchase a small 11 pound bag “Enough to last 6 life times” and it was only 5 dollars for the bag.