Mr Haidinger un a French Locality of Vauquelimte 213 



M. Breguet preserved even at the most advanced age the 

 tranquillity and gentleness of his character. The changes of 

 fortune had not altered the simplicity of his manners, and he 

 was as modest at the end of his career as when he was the 

 disciple of the Abbe Marie. His death was as calm as his 

 life. At the end of a tranquil and gay conversation, where, 

 according to his custom, he praised all the persons whom he 

 had met with during the (Jay, he went to rest, and having 

 fallen asleep, he was some moments afterwards seized with a 

 sudden illness, and expired on the 26th September 1823, at 

 the end of his 76th year. 



To his family and friends he left the tenderest recollec- 

 tions ;— to his successors, useful lessons and great models ; — 

 and to this academy a name celebrated, and a memory justly 

 honoured. 



Art. it. — Account of a French Locality of Vauquelinite. By 

 William Haidinger, Esq. F. R. S. E., &c. Communi- 

 cated by the Author. 



Among a lot of minerals, acquired last autumn from M. Rous- 

 sel in Paris, for the collection of Mr Allan, there was a speci- 

 men bearing the ticket: Plomb phosphate arsen'ifere mam^ 

 melonne de Po7it-Gibaud, Puy de Dome. It is chiefly formed 

 of two strata of the rhombohedral lead baryte, the lower one 

 gray, and with a crystalline surface ; the upper one green, with 

 a rough reniform one. Upon the latter are disposed small 

 groups of flat crystals, of a blackish pistachio-green colour, 

 yielding the characteristic siskin-green streak of Vauquelinite. 

 The small crystals were so much fractured that their form 

 could not be made out sufficiently. They appeared, however, 

 to be nearly similar to the individuals, which, in the Siberian 

 varieties, are generally joined in twins, like Fig. 6, Plate III. 



The hardness, being between 2.5 and 3.0, exactly agrees. 

 The specific gravity, which I found = 5.986 in the Siberian 

 variety, it was impossible to ascertain in the variety from 

 France, on account of the quantity of the mineral bei^g too 

 inconsiderable. 



The indications of the mineral when acted upon by the 



