The Tanning of Wood: Results

This dolphin took a bath for one week in hot water with vinegar:

This dolphin took a bath in hot alkaline water for a week:

The third one was treated with vinegar on rusty nails:

The next one took a bath in soda water:

Number 5 was boiled in oak bark and then exposed to ammonia vapor:

Here you see the dolphin swimming for 3 weeks under the ice in rainwater:

Here is the dolphin who swam in the river for a period of three weeks:

And here to compare the dolphin without any special treatment except for oil (same varnish as all the others):

And here all of them on one picture: