38 BOOK II. 



hay, which is called the cordum, is cut with scythes in the month of 

 September. Therefore in places where the grass has a dampness that is not con- 

 gealed into frost, there is a vein beneath ; also if the exhalation be excessively 

 hot, the soil will produce only small and pale-coloured plants. Lastly, there 

 are trees whose foliage in spring-time has a bluish or leaden tint, the upper 

 branches more especially being tinged with black or with any other unnatural 

 colour, the trunks cleft in two, and the branches black or discoloured. 

 These phenomena are caused by the intensely hot and dry exhalations 

 which do not spare even the roots, but scorching them, render the trees 

 sickly ; wherefore the wind will more frequently uproot trees of this kind 

 than any others. Verily the veins do emit this exhalation. Therefore, in a 

 place where there is a multitude of trees, if a long row of them at an unusual 

 time lose their verdure and become black or discoloured, and frequently fall 

 by the violence of the wind, beneath this spot there is a vein. Likewise 

 along a course where a vein extends, there grows a certain herb or fungus 

 which is absent from the adjacent space, or sometimes even from the neigh- 

 bourhood of the veins. By these signs of Nature a vein can be discovered. 

 There are many great contentions between miners concerning the forked 

 twig^^, for some say that it is of the greatest use in discovering veins, and 

 others deny it. Some of those who manipulate and use the twig, first cut 

 a fork from a hazel bush with a knife, for this bush they consider more 

 efficacious than any other for revealing the veins, especially if the hazel 



^'So far as we are able to discover, this is the first pubHshed description of the divining 

 rod as appUed to minerals or water. Like Agricola, many authors have sought to find its 

 origin among the Ancients. The magic rods of Moses and Homer, especially the rod with 

 which the former struck the rock at Horeb, the rod described by Ctesias (died 398 B.C.) which 

 attracted gold and silver, and the virgula divina of the Romans have all been called up for 

 proof. It is true that the Romans are responsible for the name virgula divina, " divining 

 rod," but this rod was used for taking auguries by casting bits of wood (Cicero, De 

 Divinatione). Despite all this, while the ancient naturalists all give detailed directions for 

 finding water, none mention anything akin to the divining rod of the Middle Ages. It is 

 also worth noting that the Monk Theophilus in the 12th Century also gives a detailed 

 description of how to find water, but makes no mention of the rod. There are two authori- 

 ties sometimes cited as prior to Agricola, the first being Basil Valentine in his " Last Will 

 and Testament" (xxiv-viii.), and while there may be some reason (see Appendix) for accepting 

 the authenticity of the " Triumphal Chariot of Antimony " by this author, as dating about 

 1500, there can be little doubt that the " Last Will and Testament " was spurious and dated 

 about 50 years after Agricola. Paracelsus {De Natura Rerum ix.), says : " These (divina- 

 " tions) are vain and misleading, and among the first of them are divining rods, which have 

 " deceived many miners. If they once point rightly they deceive ten or twenty times." 

 In his De Origine Morborum Invisibilitim (Book I.) he adds that the " faith turns the rod." 

 These works were no doubt written prior to De Re Metallica — Paracelsus died in 1541 — 

 but they were not published until some time afterward. Those interested in the strange 

 persistence of this superstition down to the present day — and the files of the patent offices 

 of the world are full of it — will find the subject exhaustively discussed in M. E. Chevreul's 

 " De la Baguette Diuinatoire," Paris, 1845; L. Figuier, " Histoire du Merveillettx dans les 

 temps moderne II.", Paris, i860 ; W. F. Barrett, Proceedings of the Society of Psychical 

 Research, part 32, 1897, and 38, 1900 ; R. W. Raymond, American Inst, of Mining Engin- 

 eers, 1883, p. 411. Of the descriptions by those who believed in it there is none better 

 than that of William Pryce (Mineralogia Cornubiensis, London, 1778, pp. 113-123), who 

 devotes much pains to a refutation of Agricola. When we consider that a century later than 

 Agricola such an advanced mind as Robert Boyle (1626-1691), the founder of the Royal 

 Society, was convinced of the genuineness of the divining rod, one is more impressed with 

 the clarity of Agricola's vision. In fact, there were few indeed, down to the igth Century, 

 who did not believe implicitly in the effectiveness of this instrument, and while science has 

 long since abandoned it, not a year passes but some new manifestation of its hold on the 

 popular mind breaks out. 



