ggg FUSION OF BARYTES, 



place, even with the strongest heat, Mr. Bucholz and I have, 

 made some experiments; to ascertain the cause of this; 

 but we have not yet attained our object. Neither an excess 

 of carbonic acid, nor the solution of part of the sub- 

 stance of the crucible, appears to be the occasion of this 

 dilference. since, on dissolving the residuum of the decom- 

 position of the nitrate in water, very little insoluble matter 

 remains in proportion to the quantity of barytes ; and on 

 adding this insoluble matter to pure barytes in much larger 

 proportion the latter is not prevented from entering into 

 fusion. 

 fr-rhap* pre- We know not whether the previous crystallization of 



irious cry-tal- k ar y tes fc e necessary to the fusion, and consequently whe- 



IiyitiCMj neces- J J . . - . . l J 



s^ry. ther water do not act some part in it. This might be solved, 



by decomposing the nitrate in a crucible of some material 



not acted upon either* by the nitrate or barytes. We made 



our experiment in a. silver crucible, but obtained no decisive 



result, on account of the large quantity of silver, which the 



nitrate detached from the crucible by cohesion. As we have 



not a crucible of gold, or of platina, we cannot pursue our 



experiment. These observations, if inserted in your AnnaU* 



may perhaps tend to an elucidation of the subject. 



Note by Mr. Descoi'ds. 



Tropfmkms of f } ie French chemists have long known the igneous fusion 



Shesulphit^ of barytes, and it was with barytes thus fused, that Mr. 



determined Thenard determined the proportions of sulphate of barytes, 



r-t* ^ wn:c h ke gave in his Memoir on Antimony, published in 



1800. It was likewise with fused barytes, that Mr.Berthollet 



has since determined the proportions of the principles of the 



same salt. As to the difference in fusibility of crystallized 



barytes and that which is obtained from the decomposition 



of the nitrate, Mr. Beithollet will make known the cause in 



a ^aper, which will be inserted in the 2d volume of the Me- 



tnoires d y Arcueil. His experiments relating to barytes were 



already finished, when I received Mr. Gehlen's letter; and 



they had given occasion to a series of researches, that are 



Water neces- now concluded. In p/Ir. Berthottet's paper it will appear, 



'° thl5 that Water is the cause of the fusibility of barytes, as the 



two celebrated chemists of Erfurt have suspected; and that 



it 



