ii Desmaresfs Map of Auvergne 75 



every detached area of basalt was faithfully represented. 

 By a system of hachures and signs the modern and ancient 

 lavas were discriminated. But he still kept the work 

 back, and when he died it remained unpublished. 



Of all his contributions to the progress of geology, this 

 map must be considered the most memorable. It was the 

 compendium of all his toil in Auvergne, and showed, as in 

 a model, the structure of the country which he had so 

 patiently and successfully elucidated. The reduced map 

 published in his first Memoir and the portions of the map 

 issued with his second Memoir, were all that he allowed 

 to appear in his lifetime, but they failed to impress the 

 minds of his contemporaries, as the entire map would 

 have done, with its complete and clear delineation of the 

 whole district. Labouring after a perfection which he 

 could not attain, he not only lost the credit which the map 

 would have brought him in his lifetime, but he retarded 

 the progress of the sound views which he himself held and 

 wished to see prevail. Had this truly admirable map been 

 published by him, together with a general description of the 

 volcanoes depicted on it, his name would have been placed 

 at once and by universal assent at the head of the geologists 

 of his day, and the miserable controversy about the nature 

 of basalt would either never have arisen, or could have 

 been speedily set at rest. Cuvier tells us that Desmarest 

 himself was fully conscious of the desirability of publishing 

 the map, but his life slipped away as he still aimed at 

 further improvement of it. Yet he could not bear that 

 other observers should enter his volcanic region and 

 describe its features. It used to be said that he seemed 

 to look on Auvergne as his own property, and certainly 



