The digestive fire or heat which causes the tardy digestion even of a scanty meal, and produces heaviness of the abdomen and head, cough, difficult breathing, water-brash, nausea, and weariness of the limbs simultaneously with the taking thereof, is called dull or sluggish (Mandagni).
The digestive fire of the Vishama kind brings on diseases characterised by the derangement of the Vayu. A keen (Tikshna) digestive fire brings on bilious (Pittaja) affections, while a sluggish (Manda) fire gives rise to diseases marked by a deranged state of the Kapham. Endeavours should be made to keep the digestive fire of the Sama type normal or regular appetite *) in an unimpaired state.
* There is a difference between "Agni" and "appetite." Agni includes bile and pancreatic secretions, and hence indicates the state of one's digestion. Appetite, though not an unerring indicator of the process, is the effect of Agni.
The one known as Vishama (irregular) should be corrected by a diet consisting of emollient, acid or saline substances. In a case of abnormally keen digestive fire, the medical treatment should consist in prescribing purgatives and a diet in the composition of which sweet, cooling, and fatty or albuminous matters largely enter. The same treatment should be adopted in (Atyagni) as marked in cases of voracious appetite, and a diet consisting of buffalo-milk, or its curd (Dadhi) and liquid buffalo-butter should be prescribed for the patient in addition. Emetics should be administered in a case of dull or sluggish digestion (Mandagni), and the patient should be restricted to a diet consisting of articles of a pungent, astringent or bitter taste.
The fire, that burns within a person, is godly in its subtle essence, and possesses the divine attributes of atom-like invisibility, weightlessness, etc., and is the digestant of food. It takes up the lymph chyle of different tastes for the purpose of digestion, and is invisible owing to its extremely subtle essence. The three vital Vayus known as Prana, Apana and Samana, located in their own spheres within the organism, feed it and keep it burning.
The three stages of man may be roughly described as (1) infancy or childhood, (2) youth or middle age, and (3) old age or dotage. Childhood extends up to the sixteenth year of life, and children may be divided into three different classes, according as they are fed on milk, or on milk and boiled rice or on boiled rice alone. A child lives exclusively on milk up to the first year of its life, it is fed on milk and boiled rice (hard food) up to the second year, and is thenceforward nourished with boiled rice (hard food).
The middle age of a man extends from the sixteenth to the seventieth year of his life, and exhibits the traits of growth, youth, arrest of development and decay.
The process of growth or building goes on up to the twentieth year of life, when youth or the age of maturity sets in and holds sway over the body of a man up to the thirtieth year of his life, - the strength, semen, and all the organs and vital principles of the body attain (their full maturity at the age of forty. Thenceforth decay gradually sets in up to the seventieth year of life. After that the strength and energy of a man dwindle day by day. The organs and virility grow weak and suffer deterioration. The hair turns to a silvery white, the parched skin looks shrivelled and becomes impressed with marks of dotage (crow's feet-marks). The skin hangs down and becomes flabby, the hair begins to fall off, and symptoms of alopecia mark the smooth, sheen and balded pate. The respiration becomes laboured and painful. The body, worn out like an old and dilapidated building, shakes with fits of distressing cough. Such a man is incapable of all acts, and does but imperfectly perform all bodily functions. He has grown old.
The dose of medicine should be increased with the age of a patient till the age of decay, and reduced after the expiry of the seventieth year to the quantity (which is usually prescribed for an youth of sixteen).
Kapham is increased during the years of childhood and Pittam in middle age; while an increase of Vayu (nervous derangement) marks the closing years of life. The use of strong or drastic purgatives, and cauterisation are alike prohibited in cases of children and old men. They should be used only in weakened or modified forms if found indispensably necessary.
It has been stated before that the body of a person is either stout, thin or of an average (middling) bulk. A stout' person should be reduced in bulk with depletive measures, while a physician should try to make a thin patient gain in flesh. A human body, which is neither too thin nor too stout, should be made to maintain its shapely rotundity.
We have already discoursed on the strength of the body. Now in a particular case under treatment, it is primarily incumbent on the physician to enquire whether the patient is naturally weak, or has become so through a deranged condition of the bodily humours or old age. And since it is the strength of a patient which makes all remedial measures (such as cauterisation, etc.) possible, it should be regarded as the grandest auxiliary to a medical treatment of whatsoever nature it may be.
There are some men who are strong though thin; while others are weak, though stout; and accordingly a physician should determine the bodily strength of a patient by enquiring about the capacity of his physical endurance and labour. Sattvam or fortitude denotes a kind of (stoic) indifference of one's mind to sensations and sources of pleasure or pain.
A man of strong fortitude (Sattvika temperament) is capable of enduring everything, or any amount of pain by repressing his mind with the help of his will or intellect. A man of a Rajasika turn of mind (strong, active, energetic) may be made to patiently submit to a course of painful medical treatment by means of persuasive counsels and the logic of the inevitable, whereas a man of a Tamasika temperament (a worldly cast of mind characterised by Nescience) is simply overwhelmed at the prospect of bodily pain.
Later on, we shall have occasion to deal with the different types of physical treatment and of remedial agents in general. A particular country, or a season of the year, a particular disease or a peculiar mode of living, any particular kind of physical labour or exercise, or the specific properties of the water of any particular locality, or day sleep, or a juice of any particular taste, is or are said to be congenial (Satmya) to a man, or a man is said to be naturalised to these conditions and environments, when they fail to produce any injurious effect on his health, though naturally unwholesome to others.
A thing of any taste whatsoever, or any kind of habit or physical exercise is said to be congenial to a man which, instead of in any way telling on his health, contributes to his positive pleasure and comfort.