The food of a human being, which is usually composed of the five fundamental material principles, admits of being classified under four different heads [as, drinks and edibles, etc.]. It has six different tastes or is of two [cooling or heat-making] potencies, or consists of eightfold properties, [viz. hot, cool, dry, expansive, slimy, mild, sharp, etc.] and of a variety of other active or efficacious virtues. The food is fully digested with the help of the internal heat and ultimately assimilated in the system, giving rise to lymph chyle (Rasa) which is extremely thin or attenuated in its consistency and which forms the essence of the assimilated food. *
The lymph chyle (Rasa), though running through the whole organism, has its primary seat in the heart, whence it flows through the twenty-four vessels which branch off from the latter (heart) to the remotest parts and extremities of the body. Of the aforesaid twenty-four vessels, ten are up-coursing, ten are down-coursing, and four have a lateral direction. The Rasa or the lymph chyle, thus flowing out of the heart, constantly soothes, maintains, and irrigates by transudation the body, and further contributes to its growth, and supports life owing to the dynamical effects of causes which lie beyond the ken of human understanding. The nature and course of this lymph chyle, which runs through the whole system, can be inferred from the growth, attenuation, or other modified conditions of the body.
* It is free from all sorts of impurities such as fecal matter, etc., and permeates the minutest vessels and capillaries.
Now it may be asked, whether the Rasa, which permeates the entire body and limbs, and which by flowing through different chambers (visceras) of the body is thus in constant contact with the excreta and other morbid humours, is of a cooling (Saumya) or heat-making (Agneya) potency?
The question may be answered by stating that, since the Rasa or lymph chyle is a fluid, and possessed of lubricating, vitalising, moistening, and nutritive (lit: - supporting) properties, it must be included within the class of Saumya (cooling) substances. The Rasa, though a Saumya fluid, obtains its characteristic pigment (Ragam) in its passage through the spleen and liver.
The Rasa or the lymph chyle, coloured through the effect of the healthy normal dyeing heat of the body, obtains the name of blood. The Rasa is transformed into the catamenial flow in women which commences at the age of twelve and ceases at fifty.
Catamenial blood, though originating from Rasa which is of a cooling potency, is fiery or heat-making (Agneya) in its character; and the fecundated or impregnated ovum (Garbha) is both cooling and heat-making in its properties on account of its partaking of the nature of both the menstrual blood (ovum) and semen which are respectively possessed of the two preceding virtues. Hence several authorities hold the blood to be identical with the life blood or with the vital principle of a living organism, and being such, to be the product of the five fundamental material principles (Panchabhautikam).
In blood the properties such as, a raw or fleshy smell, fluidity, redness, lightness and mobility, which respectively characterise the fundamental principles (of earth, water, fire, air, and sky) are to be found thus representing those specific elements in its composition.
The chyle produces blood. From blood is formed flesh. From flesh originates fat which gives rise to bones. From bones originate marrow, which, in its turn, germinates semen.
The Rasa which is originated from the digested or assimilated food and drink pre-eminently strengthens all the fundamental principles of the body.
The Purusha or self-conscious personality is Chyloborn in its origin, and hence an intelligent person should carefully preserve his bodily Rasa (lymph chyle) by adopting a proper regimen of diet and conduct.
The term Rasa is derived from the root "Ras", to go, and the substance is so called from the fact of its continually flowing through and permeating every vital principle of an animated organism.
The Rasa is successively transformed into each of the six remaining fundamental principles of the body, and continues in the shape of each for the period of three thousand and fifteen kalas five days according to our modern computation . Thus the Rasa is converted into semen, or into the menstrual blood (ovum) in women, in the course of a month. *
* The successive development of the fundamental or root principles of the body follows a distinct order. The essence of the assimilated food-matter under the heat of digestion goes towards the formation of chyle, and is ultimately transformed into it, its excreted and effete residue being passed out of the organism in the shape of stool, etc. The chyle thus produced is called the immature Rasa, or the Rasa in its nascent stage. Subsequently it enters into the bodily principle of Rasa, becomes matured by the native heat of the latter, and is resolved into three factors, or in other words, its excreted matter is transformed into phlegm, its thick or condensed portion is transformed into and assimilated in the matured Rasa of the body, whereas its subtile essence is metamorphosed into blood. The blood, thus newly generated, is merged into the fundamental organic principle of blood; and there by the heat of the latter it is again resolved into three factors, viz., its excreted portion is transformed into bile, its thick or condensed portion is transformed or assimilated into the fundamental organic principle of blood, and its subtile essence is metamorphosed into flesh. The flesh, thus newly formed, is merged into the fundamental organic principle of flesh, and there, by the native heat of the latter, it is resolved into three factors, viz, its excreted portion goes towards the formation of such excreta as are found to be deposited in the corners of the eyes and inside the integuments of the prepuce, or about the region of the glans penis, its thick or condensed portion is transformed into the organic principle of flesh and its subtile essence is metamorphosed into fat. The fat, thus newly generated, enters into the organic principle of that name, and there, by the native heat of the latter, is resolved into three factors, viz, its excreted portion is discharged through the pores of the skin in drops of perspiration, its condensed portion is assimilated in the organic principle of fat, and its subtile portion is metamorphosed into bone. Again the bone, in its nascent stage, enters into the organic principle of bone, and there, by the inherent heat of that principle, is resolved into three factors, viz, its excreted portion goes towards the formation of hairs, mustaches, etc, its thick or condensed portion is assimilated into the organic principle of bone, and its subtile portion is metamorphosed into marrow. The marrow, in its nascent state enters into the organic principle of that name; and there matured under the native heat of that principle, it is resolved into three factors, viz, its excreted portion contributes towards the formation of gelatinous matter deposited in the corners of the eyes, and the oily secretions of the skin, its condensed portion is assimilated into the organic principle of marrow, and its subtile portion is metamorphosed into semen. The semen again, in its nascent stage, enters into the organic principle of that name and there matured under its native heat is resolved into two factors, viz. thick and thin. The thick portion is assimilated into the organic principle of semen, the thin one being metamorphosed into (albumen). Semen, like gold a thousand times purified, casts off no dregs. Hence certain authorities hold albumen (protoplasmic matter) to be the eighth or the culminating principle of the body.