Having clasped the feet of the holy Dhanvantari, who had arisen out of the primordial ocean with the pitcher of ambrosia on his head, and who was the foremost of all knowers of truth. Sus'hruta interrogated him as follows: - "Tell me.O thou, the foremost of discoursers. all about the different locations and functions of the bodily Váyu (nerve force), both in its normal and agitated conditions, (as well as when it changes its natural seat through a concourse of disturbing or aggravating causes). Instruct me on the nature of distempers, which result from its deranged condition." 2.
The holy Dhanvantari, the greatest of all healers, having listened to the foregoing words of Sus'hruta, replied as follows: - This vital Vayu (nerve force), which courses through the body, is self-begotten in its origin, and is regarded as identical with the divine energy of eternal life (God), inasmuch as it is unconditional and absolute in its actions and effects, eternal and self-origin and is subtile and all-pervading (like the sky and the atom-;). It is the primary factor, which determines the principle of cause and effect in all forms of created things, whether mobile or immobile. It is so called (Váyu) from the fact of its coursing (skr. Vá - to move) throughout the universe. It determines the growth, origin and disintegration of all animated organisms, and as such, it receives the homage of all created beings Although invisible in itself, yet its works are patent or manifest. It is cold, light, mobile, dry and piercing, and follows a transverse course. It is characterised by the two attributes (proper-sensibles or Gunas) of sound and touch. It abounds in the fundamental quality of Rajas (principle of cohesion and action), is of inconceivable prowess, propels all the deranged or obstructing prinicples (Doshas) in the organism,(or in other words, is primarily concerned with the deranged principles of the body which are pathogenic in their actions). It is instantaneous in its action, and radiates or courses through the organism in constant currents. It has its primary field of action in the intestinal tract (Pakvádhána) and the rectum (Guda). In its deranged state, it is the principal factor, which, (in combination with the deranged Pittam and Kapham), lies at the root of all diseases, and is accordingly termed the king of diseases (Rogarát). 3.
* The term Nidánam, usually translated as Pathology, is meant to include factors, which fall within the respective provinces of Pathology, AEtiology, Symptomology and Pathognomy as well. For the meaning and functions of Váyu see Introduction vol. I. pp. xli. - xlii.
Now, hear me describe the symptoms, which mark the Váyu, as it courses through the organism. The Váyu, in its normal or undisturbed condition, maintains a state of equilibrium between the different Doshas and the root principles of the body (Dhátu); it further tends to maintain uniform state in the metabolism of the body, (protoplasmic, Agni*) and helps the organs of sense-perception in discharging their specific functions. The bodily Váyu, like the Pittam in the organism, is grouped under five different subheads according to the difference in its functions and locations, and is classified as the Prána. Udána, Samána, Vyána and Apána. † These five classes of Váyu, located in their specific regions, contribute towards the integration and main-tcnancc of the body *. 4 - 6