Trying to firm up the idea that vedh- means convert, transmute, or (for the philosophers among us, perhaps) transubstantiate.
The
Rasaratnasamuccaya is a kind of late-ish nibandha text that brings together, organizes and medicalizes the earlier, more tantric alchemical literature. Meulenbeld argues that it is datable to the sixteenth century (HIML IIA 670). Earliest dated MS: 1699 CE. This text is not bad as a representative of the developed ("classical"?) rasaśāstra tradition; one would expect less standardization of vocab. in earlier texts.
At
Rasaratnasamuccaya 8.94-95 there is a definition of śabdavedha.
from blowing of iron, with mercury in the mouth, there is the creation of goldenness and silverness. That is known as Word-vedha.
and the commentator makes it even more explicity that this is transmutation, using pari-ṇam.
Rasaratnasamuccayabodhinī on 8.95:
... tat lauhakhaṇḍaṃ svarṇādirūpeṇa
pariṇatam//
that bit of iron is converted into the form of gold etc.
... yatra vedhe svarṇādirūpeṇa pariṇamet sa śabdavedha ityarthaḥ//
Word-vedha is where it converts with the form of gold etc. ...
The operation being described here is not unclear. The alchemist puts a piece of mercury in his mouth and blows on a piece of iron. It becomes golden or silvery. This "becoming" is "vedha."
The Bodhinī authors were Āśubodha and Nityabodha (hence the witty title), the sons of Jīvānanda Vidyāsāgara Bhaṭṭacārya, and the Bodhinī was published in Calcutta in 1927. So it's arguable that their interpretation was influenced by 19th-20th century thought. However, their commentary is very śāstric and elaborate (note the Pāṇinian grammatical parsing, "dhama dhāvane ityasmāt lyuḥ" (>P.1.3.134 and pacādi ākṛtigaṇa). And as Meulenbeld points out, they cite an exceptionally wide range of earlier rasaśāstra texts (HIML IIA 671-2). Their interpretations are based on a close reading of classical rasaśāstra literature. At the very least, one can say that their view represents the understanding of learned panditas in turn of the century Calcutta, that vedha meant pariṇāma, or transmutation.
Best,
Dominik
Dominik