Yes, it's true that you can save the life of someone ever after your medical doctor declared the victim dead because of venomous snakebite. This is not applicable for all cases but for some.
Some claims that it is possible to give life back for a dead person if he is treated with Karutha Ummam (black Datura metel).
This is because even after the person appeared to be dead he might not be actually dead. His heartbeat, blood circulation might have stopped. Still in next 4 hours he might be alive and can give his life back if he is properly treated.
How the treatment is done?
- The First step is to put coconut oil in any one of the ear of the victim within 4 hours after his heartbeat stopped.
- Now if the oil came from another side he is dead and if the oil didn't came from another side, we can expect he is alive.
- If the oil didn't came from another side of ear, then put 3 or 5 drops of the crushed juice of Karutha Ummam leaves (name of the plant is given in Malayalam and I think in English it is called black Datura metel) into his nose.
- He will be alive shortly.
This information is provided in Siddha vaidyam of South India.
I have no guarantee regarding this. However if this information could save a man's life then it will be good.
More information about Karutha ummam can be seen here:
Usage of Datura metel for snakebites are mentioned here:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3746536/http://www.ijplsjournal.com/issues%20PD ... 2013/5.pdf