Astanga Hrudaya
स्थाप्योऽयं मध्यमः क्षारो न तु पिष्ट्वा क्षिपेन्मृदौ । निर्वाप्यापनयेत्तीक्ष्णे पूर्ववत् प्रतिवापनम् ॥ २० ॥
Preparation of mridu and teekshna ksharas (caustic alkalis of mild and strong potency) For preparing the alkalis of mild potency, the admixture of ash of shells etc. should not be made into a paste and added. But they should be added in powder form, to the solution of alkali (being prepared in iron cauldron), filtered and discarded.
english translation
sthApyo'yaM madhyamaH kSAro na tu piSTvA kSipenmRdau । nirvApyApanayettIkSNe pUrvavat prativApanam ॥ 20 ॥
hk transliteration by Sanscript