In cases that require incising, excising and scraping, alkalis or alkaline preparations are of greater importance than surgical instruments and appliances (both principal and secondary or substitutive', as they are possessed of the virtues of subduing the three deranged bodily humours such as wind, bile and phlegm).
The etymological signification of the term Kshara (alkalis) is based on their property of corroding (the skin or the flesh of an affected part of the body), or on their peculiar quality in destroying the skin and flesh where such an effect is desired. Since a variety of substances enter into the composition of Kshara alkalis , they are endued with the virtue of subduing the three deranged bodily humours. Owing to their white colour, Ksharas should be included within the category of cooling substances (Saumya).
But since many drugs or substances of a hot or fiery nature (Agneya) enter into their composition, Ksharas (alkalis) are endued with the properties of blistering, burning, suppurating (Pachana), opening etc., without involving any contradiction to their generic (Saumya) nature, and hence they are included within the list of those substances which are both hot and cooling (Saumya and Agneya in their virtues. They are pungent in taste, of a heat-making potency, irritant, digestive, corrosive, absorbent, liquefacient, improve unhealthy sores and granulation, and act as styptic and paralysing agents. They exercise destructive action on animal tissues. They are antitoxic, anthelmintic and possess the property of curing mucous accumulations in the intestines. They tend to reduce fat and phlegm and they have the virtue of destroying skin diseases. In large doses, (alkalis; have the effect of destroying the virile potency of a man.
Kshara (caustics) may be grouped under two distinct heads according to their mode of administration), such as the Pratisaraniya (for external application) and the Pania (alkaline potions . Alkaline preparations should be externally used in such skin diseases as Kitima, Dadru, Kilas, Mandala, Fistula in ano, tumour, bad ulcer (Dushta Vrana), sinus, Charma-kila, Tilkalaka, Nacchya, Vyanga, Mashaka and external abscesses and hoemorrhoids. In cases of worms and poisoning as well as in the seven forms of diseases which affect the cavity of the mouth, such as Upajihva, Upakusha, Danta-Vaidarbha, and in the three types of Rohini, external applications of alkalis act like substitutive surgical instruments. Alkaline potions or any other internal use of alkalis, should be prescribed in cases of Gulma (abdominal glands), Ascites, loss of appetite, indigestion, flatulent distension of the abdomen with suppression of stool and urine, urinary calculi, stone in the bladder, internal abscesses, worms in the intestines and hoemorrhoids, as well as for subduing or eliminating any sort of poison from the system.
Alkalis or alkaline potions will prove positively injurious to a patient laid up with fever or haemoptysis, to a man of bilious temperament, to an infant, or to an old man, and they will work similar mischief in a weak person, or in a patient suffering from vertigo, insensibility, syncope and Timira (darkness of vision). These preparations of Alkalis should be made in one and the same way by filtering; and we reserve the full description of this process for another occasion.
Alkalis for external application are prepared in three different potencies; the mild, middling and strong (extremely irritant). A physician wishing to prepare such an alkali, should first purity his body and mind, and observe a fast on a day in autumn marked by auspicious astral combinations. Then having ascended the brow of a hill, he should select a full grown Ashita-mushka (Ghanta parul) tree of middle age, and growing on soil recommended in the works on pharmacy and not anywise affected. Then having formally invoked the spirit of the aforesaid tree, which bears no white flowers) the physician should fell it on the day following, - reciting the Mantra which reads as: - "O thou possessed of mighty virtues, O thou endued with fiery potency, may thy potency never decrease or vanish. Stay here, O thou blissful one, execute my work, and after the performance thereof thou shalt be at liberty to ascend to the heavenly regions."
Then having performed the Homa ceremony with thousands of white and red flowers, the physician should cut the wood of the abovesaid tree into small pieces and put them in a place protected from the wind. Then having placed pieces of unslaked limestone over them, the physician should burn them to ashes with the lighted faggots of dried sesamum plants. Then after the fire has fairly burnt itself out, the ashes of the limestone and the Ghanta-parula wood should be separately collected and stored. Similarly the wood as well as the leaves, roots and fruits of Kutaja, Palasha, Ashva-karna, Paribhadra, Vibhitaka, Aragvadha, Tilvaka, Arka, Snuhi, Apamarga, Patala, Naktamala, Vrisha, Kadali, Chitraka, Putika, Indra-Vriksha, Asphota, Ashvamaraka, Saptachchhada, Agnimantha, Gunja, and the four species of Koshataki, should be burnt down to ashes. 11
Then a Drona measure of the ashes thus prepared * should be dissolved and stirred up in six Drona measures of pure water or cow's urine, and be filtered twenty-one times in succession. The (alkaline water filtered as above) should be kept in a large caldron over a fire and boiled by gently agitating it with a ladle. . It should be taken down from the fire when by gradual stirring, the saturated water would appear transparent, slimy, red and irritating. It should then be filtered through a piece of clean linen, and the dregs thrown away. After this a Kudava measure and a half (12 Palas) of the (abovesaid saturated or alkaline water should be taken out of the caldron, and the rest should be again kept boiling over the fire. Following this, substances known as Kata-Sharkara, the ashes of the burnt limestone previously obtained, Kshirapakas (fresh water oysters) and Sankhanabhi, should be burnt red hot in equal proportions, and then immersed and pressed in the Kudaba measure of alkaline water previously set apart in an iron basin as above described.