324 Analysis of Scientific Books. 



^arallelogrammes places les uns sur les autres ; ou algorithmique, 

 indiquant la superposition des roches et I'age de leur formation, 

 comma des termes d'une serie." And here, also, he takes occasion 

 to tell us that he has published a book •' sur I'irritation de la 

 fibre nerveuse," or " Versuche iiber die gereizte Muskel und 

 Nervenfaser," by which means we know that he writes in German 

 as well as Spanish and French, and understands the nervous 

 system as well as he does economy, geognosy, and astronomy. 



" J'ai public, J'avois, J'aifait;" I, the great, meets us every 

 "Where ; and we believe, indeed, that there is not one of his books 

 which does not contain an enumeration of all the prior ones, 

 under some pretence or other. We have not the least objection 

 that he, or any man, should write on all subjects, provided he 

 understands them ; but when we see this palpable betraying, we 

 draw the natural conclusion, that he does not write from the 

 overflowings of his mind, but because he would be thought 

 capable of writing on every thing. 



As to the purpose of this Geognostical ''pasigraphy, or any 

 purpose to be effected by it, we really cannot explain them, and 

 shall therefore extract one passage, that our readers may form 

 their own judgments. 



Si les lettres de I'alphabet repr6sentent ces roches superposees 

 des deux series, 



a, /3, y, ^ 



a, a/?, ^, /5y, y, ^ . . . . , 



la premiere indique la succession des formations simples et indfe- 

 pendantes : granite, gneis, micaschiste, thonschiefer ou mus- 

 chelkalk, gres de Konigsstein (quadersandstein), calcaire juras- 

 sique et gres vert ^ lignites (sous la craie). La seconde indique 

 Talternance des formations simples avec des formations com- 

 plexes : granite, granite-gneis, gneis, gneis-micaschiste, mica- 

 schiste, thonschiefer (pages 67, 69) ; ou, pour donner un exemple tire 

 de terrains de transition (page 103), calcaire d orthoc^ratites, cal- 

 caire alternant avec du schiste, schiste de transition seul, schiste 



et grauwacke, grauwacke seul, porphyre de transition Dans 



les formations complexes, c'est-d-dire, dans celles qui offrent 

 I'alternance periodique de plusieurs couches, on distingue quel- 

 quefois trois roches differentes, qui ne passent pas les unes aux 

 autres dans le meme groupe, 



a, $, u0y, y . . . . 

 " a^y, «/3^, ^ai 



selon que dans le terrain de transition des couches alternantes 

 de granite, de gneis et de micaschiste ; dans le terrain de tran- 

 sition, des couches alternantes de grauwacke, de schiste et de 



