1818.] M. Deodat de Dolomieu. 163 



appearance of volcanic matter, either ancient or recent ; and 

 hence deduced some general principles on the nature and cause 

 of earthquakes. 



Sir W. Hamilton having in 1785 taken a slight survey of the 

 five islands known by the general name of Ponza (Pontiae insulae 

 of Pliny), which, with the islands Ischia and Procida, form an 

 interrupted chain in front of the gulfs of Gaeta and Terracina, 

 and having observed in them many interesting geological 

 phenomena, suggested a more complete examination of them to 

 his friend Dolomieu. He accordingly visited them in the spring 

 of 1786, and brought back with him an abundant collection of 

 specimens, and many observations of great importance to the 

 general history of volcanos. These observations form the sub- 

 ject of his next publication, entitled " Memoircs sur les lies 

 Ponces," 8vo. which made its appearance in the year 1788. In 

 the preface to this work he states, that he had long contem- 

 plated a detailed history of Etna, the largest, and loftiest, and 

 most important active volcano which is readily accessible to 

 Europeans ; but that the encroachments upon his time, arising 

 from monastic disputes and the necessity of adjusting petty 

 interests, and of humiliating his adversaries, had reduced him 

 to be merely a collector of individual facts for the use of others. 

 From this complaint, which is made with some asperity, we may 

 conclude that he took a warm and active share in the intrigues 

 and dissensions which agitated the Order of which he was a 

 member, and that the foundation was here laid of those resent- 

 ments from which he suffered so severely some years after- 

 wards. 



On the breaking out of the French revolution, he returned to 

 his native country; and, following the impulse alike of his reel- 

 ings and of his friendship, arranged himself, together with the 

 Duke de la Rochefoucault, among the partisans of reform. His 

 conduct on this occasion appears to have been perfectly disin- 

 terested, for he occupied no office either of honour or profit, and 

 appears, during his residence at Paris in the first years of the 

 revolution, to have busied himself chiefly in the pursuit of his 

 favourite study, and in the publication of a few papers on subjects 

 intimately connected with it. The bloody fanaticism, following 

 close on the steps of the revolution, which swept off so large a 

 proportion of the public talent and virtue of France, although it 

 spared the person of Dolomieu, inflicted on him the irreparable 

 loss of his most intimate friend La Rochefoucault, who was bar- 

 barously murdered by a mob of assassins in the presence of his 

 mother, his wife, and his friend. During the remainder of that 

 period, emphatically called the reign of terror, proscribed, and 

 making his escape from one asylum to another, he nevertheless 

 found leisure to compose and publish two memoirs, one on the 

 figures presented by the indurated marly slates of Florence, and 

 the other on the physical constitution of Egypt. 



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