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lime is dissolved in its turn, when a residue, consisting of very fine 

 non-crystalline particles, and amounting to about two per cent, of the 

 weight of limestone employed in the experiment, is found to remain 

 undissolved. These particles consist of ar^seniferous iron-pyriteB. A 

 fact that should be noted here is, that M. Daubree formerly dis- 

 covered arsenic in the limestone of the coal-formation at Ville, and 

 found that it was contained in the rock as crystallized particles 

 of Mikspikel (Fe As-f-Fe S-), the small crystals of which were perfectly 

 recognizable. 



As regards the environs of Lobsann, it is not only in the beds 

 of lignite and bituminous limestone that arsenic is found to be pre- 

 sent. Near this locality there exist some masses of iron-ore, which 

 are very remarkable as regards their geological position. One of them, 

 at Kuhbriick, about two-and-half miles from Lobsann, furnished the 

 blast-furnaces with an hydrated oxide of iron which contained so much 

 arsenic, that it was found useless to smelt this ore any longer. These 

 masses of iron-ore " have been developed," says M. Daubree, " in a 

 series of faults {failles) with which the formation of the bitumen in 

 the tertiary formation is connected, as I have shown in another 

 memoir, so that in these deposits of such different natures, but con- 

 temporaneous, the arsenic appears to have been derived from the same 

 source." 



AVe have called attention more than once in the Geologist of last 

 year, to the beautiful researches of M. Daubree on Metamorphism, on 

 the artificial formation of many minerals, kc. ; and Professor Bunsen, 

 at the last Reunion of ]S!'atu7^alists, at Carlsruhe, declared that for five- 

 and-twenty years no work of so much importance for geology had 

 been published, as M. Daubree's researches on Metamorphism, &c. 

 We wish, therefore, that it had fallen into the plan of the late Pre- 

 sident of the Geological Society of London to have noticed the labours 

 of M. Daubree, in his yearly account of geological investigations in all 

 countries during the previous year (1857), and that he had thus added 

 the weight of his testimony to that of the many eminent foreigners 

 who have expressed their high opinion of M. Daubree's labours, as 

 the opinions and writings of English savans of so high a standing 

 have a great influence on the Continent.* 



As regards the very interesting note appended by the editor of the 

 Geologist to my last article, I must observe that I was aware that 

 the noises of guns could be heard at considerable distances, and 



* It must be remembered that the address which Dr. Phipson alludes to was 

 dehvered before the Geological Society in February of last year, and, if we re- 

 member rightly, very shortly, indeed, after the most interesting of M. Daubree's 

 researches were first published. It is somewhat unusual to notice " sins of 

 omission " in the president of a society ; but, as the remarks are evidently kindly 

 intended, we pubhsh them, in order that it may be fully known on the Continent 

 that M. Daubree's researches are not by any means slighted by English savans. 

 Indeed, Ihey were noticed with much emphasis by the present President of the 

 Geological Society, Professor Phillips, in the anniversary addi-ess delivered a few 

 days since. 



