The Four Elements

[loostudent]

I've been doing some research on elements.

Indian system

Five subtle elements (pancha tanmatras) are related to five senses: Sound (Shabda), Touch (Sparsha), Vision (Roopa), taste (Rasa), Smell (Gnadha).

Five great elements (pancha mahabhutas): the same as classic four elements with the addition of ether (akash).

Akash (Ether)

When we say Ether, words like space or a vast openness comes to one's mind. Akash means having a cavity with freedom to move. The tanmatra of ether element  is Shabda (Sound).
Whenever there is compactness of molecules, we get a dull sound on tapping but when there is a cavity or hollow space, we get a resonant sound.
The qualities of ether element are clear, light, subtle, and immeasurable. Ether element is related with various actions like expansion, vibration, non-resistance. Sensory organ related to ether element is ear as it is hollow and transmits the sound waves.

Vayu (Air)

Air is the great element that shows a sense of movement. Vayu or air initiates & directs motion or movement. Air element keeps the body in constant motion.
The tanmatra of Air element is Sparsha (Touch). The sensory organ related to Air element is skin. Skin is very sensitive for detecting any movement, change in pressure or vibration in subtle form. Any movement against skin can be easily registered.
Air element is mobile, dry, light, cold and subtle in nature. Its main action is to do any kind of movement.

Tej (Fire)

The previous element, Air performs different movements; whenever there is movement, it produces friction and leads to formation of heat or fire. This element is also called as teja or agni. All various forms of transformation including digestion of food are carried out by fire element.  
The tanmatra of fire element is Rupa (Vision). Perception of light is carries out by this tanmatra. Fire element is hot, sharp, light, dry and subtle.  
Various functions carried out by this element are penetration, digestion of food, and transformation of thoughts, intelligence and perception of light.

Jala (Water)

The fourth element is water. It is also called as jala or Apa. Whenever we think of water qualities like liquidity or fluidity comes to our mind. Water shows important quality of binding - e.g. if we see dry soil, we cannot make a ball out of it.  But if we add water to the soil, then we can easily make mud balls. This binding nature helps in forming different structures in the body as it binds the 2 cells together. Hence this element is a constructive force.
The tanmatra of water element is rasa (taste). The sense of taste or the ability to taste depends on the liquidity that exists within in the mouth in the form of saliva. Dry mouth along with dry tongue is unable to give sense of taste. The water element exhibits qualities like cool, liquid, dull soft, and sliminess. Its main actions are cohesiveness and adhesiveness.

Prithvi (Earth):

This is the last element. It is solid, dense, gross and very hard. It is related to all solid and hard structures that show shape - e.g. bones, muscles, teeth and nails. The Earth element is responsible for giving structure, shape and strength to the body.  

The tanmatra for Earth element is Gandha (Smell). The small particles of earth are scattered all over the palce gives us the sense of smell. The sensory organ related is nose. Nose is more hard compared to other sensory organs. Qualities of earth element are heavy, dull, dense hard and gross.  

Source:
http://www.ayurvedaamritvani.com/pancha-...ments.html

*Note: Some other sources connect air with smell and earth with touch.