Then having immersed eight Pala measures of the substances known as the Shankhanabhi etc., in the abovesaid alkaline water, the physician should boil it by continuous and steady stirring, care being taken not to make it of too thin nor of tod thick a consistency. Then the basin or the caldron should be taken down from the oven, and its contents poured into an iron pitcher, carefully covering its mouth after filling it. The alkali thus prepared is called the Kshara (alkali of middling potency, which, if prepared without the subsequent addition (lit : throw-over) of the ashes of Katasharkara, etc., goes by the name of mild alkali (Mridu Kshara). Similarly, alkali prepared with the addition of the powders of the drugs known as Danti, Dravanti, Chitraka, Langulaki, Putika-Pravala Talpatri, Vidha, Suvarchika, Kanaka-Kshiri, Hingu, Vacha, and Visha, or with as many of them as are available, each weighing four tolas, is called the strong Kshara (extremely irritating alkali). These alkaline preparations of different potencies, should be severally used in cases where their administrations would be clearly indicated. An alkaline preparation, any way weakened, should be strengthened by adding to it alkaline water (water saturated with an alkali) as before described.
* Two parts of the burnt ashes of Ghanla-parula and one part of the ashes of Kutaja, etc.
Authoritative verses on the subject; - The commendable features in an alkali are based on its whiteness, on its being neither too mild nor too strong, on its gloss and sliminess, on its sticking to the place of application, and on its power of secreting (Abhisyandi) the morbid fluid, and on its rapid effect. On the other hand, its defective traits consist in its being too mild, of excessive whiteness, excessive strength or irritability, of over-sliminess, excessive stickiness or thickness, insufficient boiling, and insufficiency of component ingredients.
A patient laid up with a disease amenable to an application of alkali potential cautery or caustic) should be kept in a spacious chamber, and should not be exposed to draughts and to the hot rays of the sun, [Then the physician having secured] the necessary appliances etc, as already laid down in the Chapter V (Medical Treatment Of Snake-Bites (Sarpa-Dashta Kaipa-Chikitsitam)), should view the part of the patient's body to which the alkali is to be applied. The affected part should be then * rubbed or scarified † with an alkali, and covered over‡; with a piece of linen. The alkaline preparation should be applied with a rod or director * and kept undisturbed for a period needed to articulate a hundred long letter (sounds).
Metrical texts: The perfect burning (blistering should be inferred from the black colour of the skin of the affected part. Madhuka and the substances included within the Amla-varga (group of acid drugs) pasted with clarified butter, should be applied to allay the incidental burning (sensation). A plaster composed of the shreds of Amla-Kanjika, sesamum and Madhukam taken in equal parts, and pasted together, should be applied to the part burnt with an alkali; in the event of the latter having failed to produce the desired effect owing to the disease being deeply seated. Madhukam and the Kalka paste of sesamum mixed with clarified butter would cause such an incidental; ulcer to heal.
* In a case brought about by (Pitta) ascendency of the deranged bile.
† It should be scraped with the alkali where the skin would appear hard and benumbed owing to ihe action of the deranged vital winds (Vayu).
‡ In a case of deranged phlegm (Kafa) the affected part being marked by itching and swelling.
Now you may ask the question how can an acid substance, which is fiery in its virtue and heat-making in its potency, tend to subdue the effects of an alkali which is possessed of similar virtues and properties, instead of augmenting them, as can naturally be apprehended ? Well my child, the question can be fairly answered by stating, that substances of all tastes enter into the composition of an alkali except the acid one. The pungent (Katu) taste is the principal taste of an alkali, while the saline (Lavana) forms its minor or accessory flavour (Anurasa). Now this saline taste in conjunction with the acid one renounces its extremely sharp or irritating property and is thus transformed into one of sweetness or of soothing virtue. Hence it is that an acid taste tends to allay the burning incidental to an application of alkali (potential caustic) in the same way as water tends to put out fire.
An operation of perfect cauterisation with an alkaline application brings about an amelioration of the disease, or the disease is entirely subdued, accompanied by lightness of the limbs and absence of secretion from the affected part; while an insufficient burning [of the part] is generally attended by symptoms of aggravation of the malady and also gives rise to local pain, itching and numbness. [On the other hand], excessive burning [of the part] with an alkaline preparation may have a fatal termination, and is attended by such symptoms as burning, suppuration, redness, secretion in and from the seat of affection. A feeling of languor and fatigue comes upon the patient accompanied with thirst, swooning and an aching sensation. An ulcer incidental to a burn by an alkali should be treated with a special eye to the nature of the disease and the deranged bodily humour specifically involved in the case.
A weak person, an infant, an aged person, a man of timid disposition, a patient suffering from abdominal dropsy with general anasarca or from hemoptysis, a pregnant woman, a woman in her menses, a person suffering from an attack of high fever or urethral discharges, or emaciated with chronic inflammation of the lungs, or a person subjected to fits of fainting or abnormal thirst, or a person suffering from virile impotency, or whose testes have become deranged either upwards or downwards, or a woman suffering from retroversion or introversion of the uterus or prolapsus of the vagina, should be deemed unfit for being cauterised with alkalis. Moreover their application is not to be sanctioned over the veins, nerves, joints, gristles or tender bones or cartilages, sutures, arteries, throat, umbilicus, genitals, regions of Srotas (external channels), parts covered over with a thin layer of flesh, inside the nails and other vulnerable parts of the body, nor in diseases of the eyes, excepting those which affect the eyelids.
Alkalis fail to produce any beneficial effect in a patient suffering from oedema of the limbs, or suffering from bone-ache, or laid up with a disease affecting the joints or the heart, or in a person of impaired appetite who has lost all relish for food, even when their use is otherwise indicated.
An Alkali administered by an ignorant physician is to be dreaded more than poison, fire, blows with a weapon, thunder-bolts, or death itself; while in the hand of an intelligent physician it is potent enough to speedily subdue all serious diseases in which its use is indicated.