Snake-stones also known as (the) viper's stone, (the) black stone, (der) schwarze Stein, (la) pierre noire, and (la) piedrita negra or serpent-stone are animal bones, which are widely used and promoted as a treatment for snake bite in Africa, South America and Asia. No scientific study is known which shows this remedy to be effective.

Description of use

There are differing accounts of how to use a black stone. Dr. Linnea Smith reports that in Peru, "It [black stone] is to be applied to the site of a poisonous snakebite and tied firmly in place. It is left there for several days, during which time it supposedly draws the venom from the wound. Once the poison is all removed, the ‘stone’ loosens of its own accord and falls off."

Making a black stone

Although called a stone, it is made from animal bones. When taken from snakes, it is usually from the head but also said to be extracted from the tail.

The steps suggested in this leaflet are:

• Choose a large dry cow thigh bone
• Cut it into small pieces
• Smooth them with sandpaper
• Wrap the pieces in foil
• Place in a charcoal fire for 15 to 20 minutes

Views on snake-stones expressed in scientific studies

• A Nigerian study recommended "education on the need to avoid the use of popular first aid measures of doubtful benefit." However the same doctors reported a year later that Black Stone may be beneficial.
• A Bolivian medical study stated that "contrary to widespread belief, no efficacy to treat envenomation
  Envenomation
  Envenomation is the process by which venom is injected into some animal by the bite of a venomous animal. Many kinds of animals, including mammals , reptiles , spiders , insects , employ venom for hunting and for self defense...
  
   may be expected of the BS" (black stone)
• An Indian study stated that "unscientific methods like ‘black stone’ healing contribute to the delay in seeking appropriate medical care."
• A Nigerian study found that "... black stone appears to have beneficial effects by reducing the average antivenom requirement of patients and more studies are needed ..."

Medical policy

An International Labour Organization

International Labour Organization

The International Labour Organization is a specialized agency of the United Nations that deals with labour issues pertaining to international labour standards. Its headquarters are in Geneva, Switzerland. Its secretariat — the people who are employed by it throughout the world — is known as the...

 technical workshop stated that "Local medicine, for instance black stone for snake bites, should be provided to those working in the plantations."

In Peru, Dr. Linnea Smith reports that "despite the fact that the state nursing course book admits that no evidence has ever been produced to document the effectiveness of the black stone, each student is required to make ... one ... as a part of the first aid module."

Iranian/Persian

Persian/Iranian writer Kazwini

Zakariya al-Qazwini

Abu Yahya Zakariya' ibn Muhammad al-Qazwini , was a Persian physician, astronomer, geographer and proto-science fiction writer....

describes the snake stone as being the size of a small nut. An injury inflicted by a venomous creature is to be immersed in warm water or sour milk. The snake-stone is then dropped into the liquid to supposedly draw out the poison.