The Four Elements as Sense-objects
Usually, these four elements first will have to be apprehended through any one of the 5 senses. And through each sense, they are apprehended somewhat differently in accordance with the nature of the sense-organ.
Regarding the object of the eye, there may be found two different qualities for consideration, one is the form of the object and another is the colour of it.
Hence, there are earthy forms, such as heavy looking, coarse, bulky objects. There are fiery forms, such as objects which glow or radiate light. There are watery forms, marked by their translucency or clearness and depth of appearance. And there are airy forms such as those appearing subtle.
But then, there are also earthy colours such as brown, black, or grey. There are fiery colours such as red, orange and yellow. There are watery colours as deep blue, and green. And to the wind element may be assigned the colours of white and light blue.
Similarly in regards to each sense organ.
Odours are apprehended through the nose. Thus, there are earthy odours, such as odours that are heavy, suffocating, or in some way coarse. There are odours that are of a fiery kind, such as those which have some characteristics of sharpness or stinging or burning. There are odours of a watery kind, like those that have some characteristics of moistness, clarity, or depth. And there are odours of the airy type, like odours of freshness, purity, and subtleness.
Flavours are apprehended through the tongue. So there will be earthy flavours, like heavy or nutty flavours, salty and peppery flavours, or any flavour of a coarse type. There are fiery flavours, as spicy, or biting flavours as bitter and sour. There are flavours of a watery kind, such as clear, easy down flowing flavours such as sweetness, or flavours with some characteristics of wateriness, such as those of salads and fruits. And there are flavours of the airy kind, such as flavours that are rather plain, subtle or tasteless.
Similarly with the element of sound, apprehended through the ear. There are earthy sounds, that are heavy, coarse, or painfully loud. There are sounds that are fiery, such as forceful or glorious kinds of sound. There are also sounds that are of a watery nature, such as sounds that are characterised by clarity and depth. And there are equally sounds of an airy nature such as sounds that are sounding very swift, fast, and subtle.
Concerning tangibles, there are those of an earthy kind, such as what feels solid, hard, or heavy. Tangibles of a fiery type, are experiences of heat, sharpness, or pain. A touch of a watery kind is what feels liquid or is experienced as possessing depth. And tangibles of an airy kind will be experienced as movement, fluctuation, or as subtleness.
Each of those sensory experiences, in turn, is conveyed via a certain medium. Thus, the main medium for the conveyance of forms and colours to the eye is the element of light (an element belonging to the fire element). The main medium for conveying tastes to the tongue is the element of water (viz. saliva). The main medium both for conveying smells to the nose and sounds to the ear is the element of air. And in regards to touch is the earth element the main medium of conveyance.
Thus may the whole of sensual experience be fitted into this basic scheme of classification.