Rasahṛdayatantra (1728 manuscript)

i. 90

...with the taila-ardha-puṭa half-oil firing, one should place the seed at an equal time. [7] With twenty times the strength, the mercury is joined by the sāraṇa method. Here, the iron, once weakened, becomes unified with the essence and becomes firm. [8]

After the bīja-sāraṇa seed-transmutation, the kanaka-sāraṇa gold-transmutation is described:

One should transmute the rasarāja king of mercury in the bhīta-mūṣā terrified/shaken crucible with twice the amount of the kanda bulb/root essence. [9] Another method: one should transmute the seed with three times the amount of red [substance]. Add a little lead. There are three types of sāraṇa operations. [10]

The sāraṇa apparatus (yantra):

Make a long apparatus of three types, without a pipe or tube, with a clear crucible hole, [11] In this, the crucible is placed with the sāraṇa oil, and the equal amount of gold is added. The mixture unites with the rasarāja. [12]

Another apparatus:

A tube, six fingers long, resembling a flower, attached to the crucible, through which the gold is poured. [13]

Another apparatus:

Another tube, one finger in width and six fingers in length. It must be made firm and comfortable. [14] In this, the mercury is placed, mixed with sāraṇa oil. When it faces down, it produces gold. [15] In this crucible, make the tube face downward. The essence will undoubtedly be unified. [16]

Another apparatus method:

Make an eight-finger crucible, with a mouth resembling a flower. [17] Another one with a hole, seven fingers long. [18] Placing the mercury and the oil together, one should perform the task with a well-made crucible. [18]

Another method:

The tube is made with intelligence. This is the method for the day of accomplishment. [19] Having placed the sāraṇa oil for a year, one should place the seed in the crucible. [20] With clear flames underneath, one should apply the fire. The mercury will undoubtedly be attached to the seeds above. [21]

Another method:

Make it in such a way, with a half-finger wide tube. By this method, the mercury is placed above the seed. [22] With the mouth blocked according to the rules, the seed is placed for the breaking of iron. Knowing this, one should not overdo the permeation of the rasarāja. [23]