296 MESSES. G. A. J, COLE AND J. W. GREGORr 



figured and described by Aldrovandus * in 1648, but no definite 

 opinion as to the nature of the rock of this localitj^ can be obtained 

 from his work. A figure, however, given by Langius t, in 1705, of 

 a " variolites Lucernensis " from the Emmenthal is unmistakable. 

 The rock was subsequently described from other localities, as by 

 Bruckmann X in 1734 and by Demeste § from the bed of the Durance 

 in 1779. Wallerius || in 1747, and Bertrand ^ in 1763, published 

 classifications of Yariolite, as by this time different rocks had been 

 included under the same name. Hitherto pebbles only had been 

 found, but in 1775 the Abbe Rozier's ' Journal ' ** announced its 

 discovery m situ in the " Servieres " valley, by MM. Faujas de 

 St. Fond and Guettard ; the former, however, gave in 1781 tf an 

 account of his observations, and from this it is obvious that he and 

 his companion had only found fallen masses of rock on the 

 talus-slopes ; in the same contribution Faujas called the Durance 

 rock " lapis variolatus viridis verus/' to distinguish it from the 

 amygdaloids that had been confounded with it. Valmont de Bomare's 

 discovery of native silver in the Yariolite of the same district led him 

 to examine it, with the result that he contended for JJ the common 

 origin of varioles and ground-mass (or " variolin " as it was called 

 by Delametherie). 



Though Buffon §§ had in 1786 clearly indicated Mont Genevre as 

 the source of variolite, Morozzo !||| threw doubt on its occurrence 

 there. Fournet's elaborate " Memoire sur la geologic de la partie 

 des Alpes comprise entre le Yalais et I'Oisans," ^% contained an 

 important addition to the knowledge of variolite : from his de- 

 scriptions *** he seems to have collected, probably from the bed 

 of the Durance, compact diabase, perlitic variolite, and porphyritic 

 diabase. Elie de Beaumont probably found variolite in situ, 

 but no record of his observations seems to have been published, and 



* Aldrovandus, UL, ' Musasum Metallicum in libros iiii. distributum ; ' 

 Bononire : 1648 : p. 883. 



t Langius, Cai'l Nic, ' Historia Lapidum figuratorum Helvetiae ejusque 

 Ticiniaj ; ' Lucerna : 1705, pp. 40-1. 



j Bruckmann, ' Centuria Epistolarum Itinerarium,' vol. i. ep. xxxi. Wolf- 

 fenbutteljB, 1742. 



§ ' Lettres du Doct. Demeste au D. Bernard sur la Chyraie, Docimasie,' &c. 

 Paris, 1779 (quoted bj^ Buflfon). 



II Wallerius, ' Mineralogia, Eller Minei'al-Riket, Indelt och beskrifvir,' 

 Stockholm : 1747, p. 409 (French edition, 1753). 



^ E. Bertrand, ' Dictionnaire raisonne iiniversel des fossiles propres et des 

 fossiles accidentels,' Le Hage, 1763, t. ii. pp. 238-9. 



*'*■ "Observations sur la physique," t. xvi. (1775) p. 517. 



i'i" Faujas de St. Fond, ' Histoire Naturelle de la province de Dauphine,' 

 Grenoble : 1781, t. i. p. 253. See also Faujas de St. Fond, ' Histoire Naturelle 

 des Roches de Trapp,' ed. 2 (Paris. 1813), p. 26, footnote. 



\l 'Dictionnaire raisonne universel d'Histoire Naturelle,' t. viii. Lyon : 1791. 



§§ ' Histoire Naturelle des Mineraux; sur la variolite du Piemont,' t. iv. (Paris , 

 1786) pp. 395-8. 



II II Mem. Acad. Roy. Sciences (Turin), vol. v. 1793, pp. 165-72. 



■[[•[ Ann. des Sci. Physiques et Nat. Soc. Roy. d'Agric. Lyon, ser. i. t. iv. 

 (1841) pp. 105-183, 483-560 ; ix. (1846) pp. 1-112 ; ser. ii. t. i. (1849) pp. 185- 

 2(n), pi. i. 



*** Fournet, ibid. ser. i. t, iv. p. 155. 



