Spit is composed of a mixture of saliva and mucus, and is ejected from the mouth, usually at high speed by many earthbound creatures. Biologically, spitting serves a single purpose: the removal of excess mucus and saliva from the body. Socially, it serves many different purposes.
As a Sign of Disgust
To spit at someone is a sure sign of disgust in almost all cultures. However, among the Fremen of Arrakis1, spitting is a gesture of great reverence, due to the scarcity of water.
Spitting in the Media
In the film Titanic, the Kate Winslett/Leonardo DiCaprio version, Leo teaches Kate to spit.
On one of the Monkey Island computer games, you have to cheat in order to win a spitting contest with some pirates.
There is a small MTV computer game called 'Beavis and Butthead's Hockaloogie'.
Spitting in Society
Tobacco chewers find opportunity to take part in 'Spitting Contests' at county fairs in America. In these competitions, chewers spit tobacco juice and are judged on distance and accuracy. For distance, spitters line up and spit with all their might. For accuracy, a target is painted on a metal coal stove. The spitter who hits the stove will be rewarded with a satisfying 'hiss' of spit on hot metal. Of course, closest to the centre of the target is the winner.
Children get into imitating these contests with 'Tootsie Roll Spitting Contests', the object of which is not to spit out a Tootsie Roll, but rather to suck on it until the mouth fills with chocolate and then to spit out the juice for distance and accuracy much like tobacco spitting contests.
Baseball players are notorious for their spitting. Invariably, when watching a baseball game, you'll see someone spit. Many chew tobacco and spit out the juice. Others chew sunflower seeds and spit out the shell husks.
Strength and Virility
Among the great legends of piracy upon the high seas are those related to spitting, for pirates were renowned for their skill with spittoons2 and spitting contests. Children also enjoy the social activity of spitting, especially over water. Bridges are ideal for this sport.
Classifying the different types of spit is important when playing competitively.
Glob or Gob - The standard spit, a globule of pure saliva.
Orbiter - Two globs of spit attached by a thin wire of spit. This is difficult to achieve.
Stringer - A watery spit with some mucus. This is not fully released from the mouth as it stretches outwards thus reducing distance. This method is sometimes frowned upon in spitting circles. However, should a stringer reach an abnormally long way down, these are often very well received.
Froth/Cappuccino - The froth is caused by aerating the saliva before firing. A certain amount of mucus is helpful to keep it together, and looks very impressive when landing on a watery surface. The Cappuccino is the poetic name for this spit.
Cluster Bomb - These have very little mucus indeed. They do not remain together, and scatter over the playing surface. The distance achieved is difficult to measure, thus a low score rating is accredited to this method.
Greeny/Greenie - A spit with a large proportion of mucus. Named due to its colouration, greenies are notoriously slimy and remain together. They adhere strongly to surfaces. Greenies are highly rated in scoring.
Spitting in the Animal World
Many animals spit, most notably the llama and the camel. By all reports these two fellows can also be quite vicious if the mood takes them.
Spitting as a Manifesto
For many, spitting is viewed as a human right, and for them, the oppression of this right demands immediate and unilateral discussion.