BOOK I. 



even tin and bismuth 6 are treated differently from lead. Although the 

 evaporation of juices is an art apparently quite distinct from metallurgy, 

 yet they ought not to be considered separately, inasmuch as these juices 

 are also often dug out of the ground solidified, or they are produced from 

 certain kinds of earth and stones which the miners dig up, and some of the 

 juices are not themselves devoid of metals. Again, their treatment is not 

 simple, since there is one method for common salt, another for soda 7 , 

 another for alum, another for vitriol 8 , another for sulphur, and another 

 for bitumen. 



Furthermore, there are many arts and sciences of which a miner should 

 not be ignorant. First there is Philosophy, that he may discern the origin, 

 cause, and nature of subterranean things ; for then he will be able to dig 

 out the veins easily and advantageously, and to obtain more abundant results 

 from his mining. Secondly, there is Medicine, that he may be able to look 

 after his diggers and other workmen, that they do not meet with those 



" Galen calls the metallic earth a compound which is really a mixture, but he who wishes to 

 " instruct others should bestow upon each separate thing a definite name." 



For convenience of reference we may reduce the above to a diagram as follows : 

 i. Fluids and gases. 



Earths 

 (a) Simple 



A. Homogenous 

 bodies 



minerals 



Solidified juices 



Stones 



Metals 



(b) 



2. Mineral/ 

 bodies i 



Compound i Being homogenous mixtures 

 minerals 1 of (a) 



B. Mixtures. Being heterogeneous mixtures of (a) 



...'.. plumbum .... candidum ac cinereum vel nigrum. " Lead 



" . . . white, or ash-coloured, or black." Agricola himself coined the term plumbum 



cinereum for bismuth, no doubt following the Roman term for tin plumbum candidum. 



The following passage from Bermannus (p. 439) is of interest, for it appears to be 



the first description of bismuth, although mention of it occurs in the Nutzlich Bergbuchlin 



(see Appendix B). " Bermannus : I will show you another kind of mineral which is numbered 



amongst metals, but appears to me to have been unknown to the Ancients ; we call it 



bisemutum. Naevius : Then in your opinion there are more kinds of metals than the 



seven commonly believed ? Bermannus : More, I consider ; for this which just now I 



said we called bisemutum, cannot correctly be called plumbum candidum (tin), nor nigrum 



(lead), but is different from both and is a third one. Plumbum candidum is whiter and 



plumbum nigrum is darker, as you see. Naevius : We see that this is of the colour of 



galena. Ancon : How then can bisemutum, as you call it, be distinguished from galena ? 



Bermannus : Easily ; when you take it in your hands it stains them with black, unless 



it is quite hard. The hard kind is not friable like galena, but can be cut. It is 



blacker than the kind of rudis silver which we say is almost the colour of lead, and thus 



is different from both. Indeed, it not rarely contains some silver. It generally indicates 



that there is silver beneath the place where it is found, and because of this our miners 



are accustomed to call it the 'roof of silver.' They are wont to roast this mineral, and 



from the better part they make metal ; from the poorer part they make a pigment of a 



kind not to be despised." 



''Nitrum. The Ancients comprised many salts under this head, but Agricola in the 

 main uses it for soda, although sometimes he includes potash. He usually, however, refers 

 to potash as lixivium or salt therefrom, and by other distinctive terms. For description 

 of method of manufacture and discussion, see Book XII., p. 558. 



8 Atramentum sutorium " Shoemaker's blacking." See p. 572 for description of method 

 of manufacture and historical footnote. In the main Agricola means green vitriol, but he does 

 describe three main varieties, green, blue, and white (De Natura Fossilium, p. 219). The blue 

 was of course copper sulphate, and it is fairly certain that the white was zinc vitriol. 



