Sartha Guna (substance or essence) is also known as senses. Senses have a very vital role to plays in growth and functioning of human beings.
Each of the 5 senses or indriya co-ordinates with each other and maintains a perfect balance with the nature.
There are five essential senses that are related to human beings.
They are Sound (Shabda), Touch (Sparsha), Vision (Rupa), Taste (Rasa), Smell (Gandha). The description of each of the sartha guna is as follows:
In Sanskrit language, it is known as Shabda. It is one of the belongings of space or aakasha mahabhoota (one of the main constituent of panchamahabhoota). It is interesting to note that besides space element every mahabhoota (constituent or element) have the essence of sparsha guna.
Three things are responsible for the creation of sound on earth. Even, the machines, be it of any kind when turned into operational mode produces a sound. Devices that create any kind of sound such as broadcasting sounds are the contributory causes whereas Sanyoga, Vibhaga and Shabda are emulated factors. They are: Sanyog (Combination), Vibhaga (splitting) and Shabda (Sound).
It means combination or amalgamation of two things. For instance, when any kind of object is hit, it produces a sound.
It means splitting or separation. For instance, on being split into two parts, a paper (soft or hard material) always produces a sound.
It means a particular sound produces another kind of sound. According, to ayurvedic system of medicine, Shabda is divided into Dhwanitmak (sound) and Vanitmak (letters). Shabda forms an important part of human speech therapy.
In Sanskrit language, it is known as Sparsha. It is felt by the skin (Tvak Indriva) and it is the main attribute of Vayu Mahabhoota (Air element). Sparsha is classified into 3 categories, which are Cold (Shita), Hot (Ushna) and Anushnashita (Neither cold nor hot).
In Sanskrit language, it is called Rupa. Besides, air and space element (mahabhoota) every other element possess rupa guna. It is the key guna of teja (fire) element and is categorized into 7 parts, i.e. White (shukla or shweta), Blue (Nila), Yellow (pita), Green (harita), Brown (kapish), Red (rakta; identification with blood) and Spotted or Marked (chitra).
The jal mahabhoota or water element is sometimes signified by dull white color (shweta) and earth element or prithvi mahabhoota is signified by all sapta rupa guna (seven rupa guna).
In Sanskrit language, it is called Rasa. This is a kind of guna which is sensed or felt by tongue. The contributory causes that create rasa guna are panchamahabhootas. There are 6 kinds of rasa guna, i.e. Sweet (madhur), Sour (amla), Salt (lavan), Bitter (tikta), and Chilly (katu), Taste like Alum (kashaya).
In Sanskrit language, it is called Gandha. Gandha guna is taken or received in the body by nose (by nasal passage). This guna is there in earth element or prithvi mahabhoota. Good Smell (surbhi) and Bad Smell (asurbhi).