LIFE AND WORKS OF NICOLAUS STENO XXV 



theories, which were most generally accepted, tended towards the ex* 

 planation that, like so many other bodies which were found in the 

 earth and exactly resembled parts of animals or plants, they had been 

 formed in the earth, at the place where they were found, either by a 

 force inherent in the earth (vis plastica), by a lusus Naturx, or by the 

 Creator himself; and as to the immanent forces of these bodies the curs 

 rent opinions were alike unscientific. Contrary to most of the natu? 

 ralists of those days Fabio Colonna had declared glossopetrx to be simply 

 sharks' teeth in a fossil state. This also was Steno's opinion, and per? 

 ceiving how close was the resemblance between sharks' teeth and the 

 glossopetrx, and furthermore taking into account the nature of the soil 

 in those parts where glossopetrx were round, he was, through the fol* 

 lowing considerations, led to nothing less than the foundation of 

 scientific geology; for he rightly perceived that what was true in the 

 case of sharks' teeth, was necessarily also true in the case of all other 

 parts of animals or plants found in the earth, and the six conjecturx 

 he laid down consequently comprised all such bodies: 1. Terra, imde 

 animalium partibus similia corpora eruuntur, corpora ilia hodie non pro= 

 ducere videtur. 2. Eadem terra non videtur fuisse compacta, cum prxdicta 

 corpora ibi producta sunt. 3. Nee forte repugnat, qvo minus eandem 

 terram aqvis olim tectam fuisse credamus. 4. Nihil qvoqve obstare videtur 

 qvo minus credamus, eandem terram aqvx olim fuisse immixtam. 5. Nee 

 qvicqvam obstare video, qvo minus eandem terram pro aqvx sedimento 

 sensim congesto habeamus. 6. Nihil obstare videtur, qvo minus anima= 

 Hum partibus similia corpora, qvx e fern's eruuntur, pro animalium parti= 

 bus habeantur. Steno gave good reasons for these conjectures; but as 

 to his proofs reference must be made to the work itself. One point, 

 however, is still to be mentioned, that in his list of contents Steno 

 says that in earth from Malta are found vertebrae of fishes, closely 

 resembling a vertebra still sticking in the clay, which Fr. Maria Fio= 

 rentini had shown to him, a circumstance which certainly strengthened 

 his opinion concerning the nature of the glossopetrx. Finally Steno 

 touched upon the question of the way in which mineral substances 

 come to fill up the spaces formerly occupied by organic bodies, having 

 cast themselves entirely in the mould of the latter. 



As mentioned above the large, geological work, which Steno in? 

 tended to write, was never accomplished, and only a Prodromus is 

 extant. Because of the brief and condensed form of this work, so 

 abounding with new ideas, it is impossible to give an account of it in 

 a still more condensed form. Here again the reader must be referred 

 to the book itself, though a few remarks on the state of geology at 

 the time of Steno might perhaps be appropriate in this connection. It 

 was universally taken for granted that the Earth had come into exi* 

 stence only a few thousand years ago, created in the way which has 



