232 NICOLAUS STENO 



7. Either in the rock of the mountains themselves, or in their 

 neighborhood, very clear traces of subterranean fire; just as 

 many springs are found around hills which are made up o£ 

 strata of earth. And here it must be observed in passing that 

 the hills which are formed of earthy strata, for the most part, 

 have as their foundation larger fragments of stony strata ; these 

 in many places keep the earthy strata placed upon them from 

 being swept away by the current of neighboring rivers and 

 torrents. Further, they often protect entire regions against the 

 violence of the ocean, as the extended reefs of Brazil ^ and 

 exposed craggy shores everywhere bear witness. 



Mountains can also be formed in other ways, as by the 

 eruption of fires which belch forth ashes and stones together 

 with sulphur and bitumen; and also by the violence of rains 

 and torrents, whereby the stony strata, which have already be- 

 come rent apart by the alternations of heat and cold, are 

 tumbled headlong, while the earthy strata, forming cracks 

 under great blasts of heat, are broken up into various parts. 

 And from this it is clear that the chief classes of mountains and 

 hills are two : first, of those which consist of strata ; of ;these 

 there are two kinds, since in some, strata of rock prevail, in 

 others, strata of earth. The second class is composed of moun- 

 tains which rise without order or arrangement from fragments 

 of strata and from parts, further, which have been worn away. 



Hence it could be easily shown : 



I. That all present mountains did not exist from the begin- 

 ning of things. 

 P. 34. 2. That there is no growing^ of mountains. 



1 Steno's information regarding Brazil was probably gained from a book called Historia 

 Naturalis Brasiliae, Amsterdam, 1648. The volume contains Piso's De Medicina Brasiliensi 

 Libri Quatuor, and George Musgrave's Historiae Rerum Naturalium Brasiliae Libri Octo. 

 No doubt Casper Barlaeus's Rerum fer Octennium in Brasilia sub Praefectura Mduritii 

 Nasovii Historia (Amsterdam, 1647) was also known to him. 



Willem Piso (1611-1678) was a member of the Brazilian expedition of Count Jan Maurits 

 from 1636 to 1644. Steno had known Piso in Leyden and in 1664 addressed to him the letter 

 on the Anatomy of the Ray {De Anatome Rajae Epistola) printed by Maar, Opera Philosophica, 

 Vol. I, pp. 193-207. Robert Boyle refers frequently to Piso's History of Brazil. 



^ Steno's word is vegetatio, which suggests the growth of an organism ; but he does not 

 hesitate to use crescere of inorganic accretions. The passage quoted by Maar, op. cit.. Vol. II, 

 p. 338, from Fabronius {Vitae Italorum (p. 202), Vol. Ill, p. 72), is singularly apposite. In 



