From Thomas Nicols (1652) Lapidary, Or, The History of Pretious Stones. Part II, Chap. XXXVI, pp. 158-159:
Of the Garatromo or Toadstone.
This stone is of a brownish colour somewhat tending to rednes, convex on the one side; & on the other side, sometimes plain, sometimes hollow.
Some say this stone is found in the head of an old Toad; others say that the old toad must be laid upon the cloth that is red and it will belch it up, or otherwise not; you may give a like credit to both these reports, for as little truth is to be found in them as may possibly be: Witnesse Anselmus Boetius in lib. 2 in the chapter of this stone; who saith that to try this experiment in his youth he took an old Toad and laid it upon a red cloth and watch it a whole night to see it belch up its stone, but after his long and tedious watchfull expectation he found the old Toad in the same posture to gratifie the great pains of his whole nights restlessenesse, and since that time he taketh that stone which is called Garatromo or the Toad-stone, to be an obscure Starre-stone.
Its names.
This stone is called Batrachites, and Brontia, and Ombria, and Garatronium, Lapis Borax, Lapis Bufonis, Lapis Rubetæ. In French, un Crapaut & Crapaudine. In Germanne ein Krattenstein. Some in Latine call it Crapontina. In English a Toadstone.
Of its kinds.
Baccius maketh two kinds of this stone: One of a whitish brown colour: another of a black colour with a bluish eye.
This stone saith Boetius is sometimes found of the bignesse of an egg, and those that are so great, are sometimes brownish, sometimes reddish, sometimes yellowish, sometimes greenish.
Some are no bigger then the nail of the hand and these by Jewellers are taken for the true Toad-stones.
It is reported of it that it is good against poyson if it be worn so as it may touch the skin, and that if poyson be present it will sweate, and that if any inflations procured by venemous creatures be touchd with it, it will cure them. So saith Weckerus, Lemnius, and Baccius.
From Daniel Widdowes alias Woodhouse (1631) Naturall Philosophy: Or Description of the World, and of the Severall Creatures therein contained, Viz. Angels, Mankind, Heavens, Stars, Planets, Elements, with their order, nature and government: As also of Minerals, Mettals, Plants and Precious stones; with their colours formes, and vertues. Second Edition, corrected and enlarged. (All of this contained in the space of 63 pages), p. 29:
The Ruber or Toadstone, groweth in the head of a Toad: It is of a white browne colour, sometime it hath a skie coloured eye in the middle: It is to bee taken before the Toad touch any Water. It is a remedie against all poyson. If it come neere poyson, it changeth colour, and sweateth as it were drops.
From Edward Topsell (1608) Historie of Serpents , pp. 188-189:
There be many late Writers, which doe affirme that there is a precious stone in the head of a Toade, whose opinions (because they attribute much to the vertue of this stone) it is good to examine in this place, that so the Reader may be satisfied whether to hold it as a fable or as a true matter, exemplifying the powerfull working of Almightie God in nature, for there be many that weare these stones in Ringes, being verily perswaded that they keepe them from all manner of grypings and paines of the belly and the small guttes. But the Art (as they terme it) is in taking of it out, for they say it must be taken out of the head alive, before the Toad be dead, with a peece of cloth of the colour of red Skarlet, where-withall they [sc. the toads] are much delighted, so that they stretch out themselves as it were in sport upon that cloth, they cast out the stone of their head, but instantly they sup it up againe, unlesse it be taken from them through some secrete hole in the said cloth, whereby it falleth into a cestern or vessell of water, into which the Toade dareth not enter, by reason of the coldnes of the water. These things writeth Mossarius.
Brasavolus saith, that he found such a thing in the head of a Toade, but he rather tooke it to be a bone then a stone, the colour wherof was browne, inclyning to blacknes. Some say it is double, namely outwardly a hollow bone, and inwardly a stone contained therein, the vertue whereof is said to breake, prevent, or cure the stone in the bladder. Now how this stone should be there ingendered, there are divers opinions also, & they say that stones are ingendered in living creatures two manner of wayes, either throuh heate, or extreame cold, as in the Snaile, Pearch, Crabbe, Indian Tortizes and toades; so that by extremitie of cold this stone should be gotten.
Against this opinion the colour of the stone is objected, which is some-times white, sometimes browne, or blackish, having a cittrine or blew spot in the middle, sometimes all greene, wher-upon is naturally engraven the figure of a Toade: and this stone is somtimes called Borax, sometimes Crapodinæ, and sometimes Nisæ, or Nusa, and Chelonites. Others doe make two kindes of these stones, one resembling a great deale of Milke mixed with a little blood, so that the white exceedeth the Redde, and yet both are apparant and visible: the other all blacke, wherein they say is the picture of a Toade, with her legges spredde before and behind. And it is further affirmed, that if both these stones be held in ones hand in the presence of poyson, it will burne him. the probation of this stone, is by laying of it to a live Toade, and if she lift up her head against it, it is good, but if she run away from it, it is a counterfeyte.
Geor: Agricola calleth the greater kind of these stones, Brontia, and the lesser & smoother sort of stones, Cerauniæ, although some cõtrary this opinion, saying that these stones Brantia & Cerauniæ, are bred on the earth by thundering and lightning. Whereas it is said before, that the generation of this stone in the Toade proceedeth of colde, that is utterly unpossible, for it is described to be so solid and firme, as nothing can be more had, and therefore I cannot assent unto that opinion, for unto hard and solide things, is required abundance of heate: and againe, it is unlikely, that whatsoever this Toad-stone be, that there should be any store of them in the world as are every where visible, if they were to be taken out of the Toades alive, and therefore I rather agree with Saluedensis a Spaniard, who thinketh that it is begotten by a certaine viscous spume, breathed out uppon the head of some Toade, by her fellowes in the Spring-time.
This stone is that which in auncient time was called Batrachites, and they attribute unto it a vertue besides the former, namely, for the breaking of the stone in the bladder, and against the Falling-sicknes. And they further write that it is a discoverer of present poyson, for in the presence of poyson it will change the colour. And this is the substaunce of that which is written about this stone. Now for my part I dare not conclude either with it or against it, for Hermolaus, Massarius, Albertus, Sylvaticus, and others, are directlie for this stone ingendered in the braine or head of the Toade: on the other side, Cardan and Gesner confesse such a stone by name and nature, but they make doubt of the generation of it, as others have delivered; and therefore they beeing in sundry opinions, the hearing wereof might confound the Reader, I will referre him for his satisfaction unto a Toade, which hee may easily every day kill: For although when the Toade is dead, the vertue thereof be lost, which consisted in the eye, or blew spot in the middle, yet the substaunce remaineth, and if the stone be found there in substance, then is the question at an end, but if it be not, then must the generation of it be sought for in some other place.
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