82 ALEXANDER VON HUMBOLDT. 



chapter concludes with a dissertation on the lapis heraclius 

 of the ancients. 



In this work on basalt Humboldt displays rare powers of 

 observation, a clear mode of description, and an extensive ac- 

 quaintance with literature. He is here discovered to be not 

 merely a mineralogist and a geologist, but also a botanist. 

 The plants which he found growing on the basaltic rocks of 

 the Rhine are compared with those he had previously gathered 

 from the basalt of the Meissner, and he enters into a searching* 

 criticism of the observations of Collini and De Luc. ' Every- 

 thing,' writes Forster, 6 upon which I had touched in few 

 words concerning the supposed volcanoes on the Rhine, finds 

 full confirmation in the two quartos of Dr. Nose, as well as in 

 the condensed observations of our acute friend Alexander von 

 Humboldt.' His ingenuity was mainly directed to the support 

 of the erroneous theory of the aqueous origin of basalt, at that 

 time prevalent among geologists ; and the influence of the work 

 was so considerable, that the book was often appealed to in sup- 

 port of those views long after the author himself had renounced 

 them in favour of the volcanic theory. 



The extravagant length to which the science of geology 

 had been carried by these fantastic speculations on the nature 

 of basalt is strikingly seen in a polemical treatise by the 

 learned Professor Witte, 1 of Rostock, Counsellor of the Duchy 

 of Mecklenburg. He explained the Pyramids of Egypt to be 

 the remains of a volcanic eruption, c which had forced its way 

 upwards with a slow and stately motion,' the hieroglyphics 

 upon them as crystalline formations, the lake of Moeris as the 

 sunken crater of an extinct volcano, the well or shaft of the 

 great Pyramid as the air-hole of a volcano, the sarcophagus 

 of Cheops as two pieces of lava, which, lying one over the 

 other ' like a couple of biscuits,' before completely cooling, 

 had taken the form of a coffin, &c. Even the ruins of Perse- 

 polis, Balbec, Palmyra, the temple of Jupiter at Grirgenti in 

 Sicily, the two palaces of the Incas of Peru, at Lacatagua and 

 Alkunkanjar, were supposed to be natural formations of basalt 

 and lava. 



1 ' Ueber den Ursprung der Pyramiden in Aegypten und die Ruinen von 

 Persepolis.' Leipzig, 1789. 



