ON THE METALS OF THE ALKAUf. 



resntU are obtained only so far as there is moisture in thri 

 vessels employed. On this point we cannot accede to ihe 

 opinion of Mr. Davy : neither our gasses, nor our mercury, 

 nor our vessels, contain water; and yet we always obtaia 

 from this ammoniuret the 0*4 of ammoniac without being 

 ■»* decomposed. This dift'erence between our results and those 

 of Mr. lyiivy does not depend on water, as he supposes, but 

 on the high temperature, to which he exposes the ammo- 

 niuret.'* 



Under the 3d head Mesf rs. Gay-Lussac,and Thenard say : 

 l«!pliOTet and ** On treating the sulphurets and phosphurets of potas- 

 S^fum^' *^sium with an acid, assisted by heat, as ought to be doxit, 

 fceated with neither hidrogurelted sulphur, nor hidroguretted phospho- 

 WMid. ,.yjj^ is formed; and we always obtain even more phosphu- 



retted hidrogen,thanis requisite to represent the hidrogen of 

 the potassium. 



*' Mr. Davy says, 1st, on treating the sulphuret of potas- 

 sium with muriatic acid, he has obtained very variable 

 quantities of sulphuretted hidrogen gas; and that in gene- 

 ral less is evolved, than the potassium of this fculphuret 

 would disengage of hidrogen from water: 2dly, that, on the 

 contrary, on treating potassium with sulphuretted hidrogen 

 gas, there is a greater quantity of h.drogen gas set free, than 

 that which the potassium employed is capable of evolving in 

 its contact with water. 



**We have repeated more than fifty times our experi- 

 ments on sulphur, sulphuretted hidrogen gas, and potas- 

 sium : the sulphuret cf potassium has always afforded us by 

 Acidsa quantity of sulphuretted hidrogen gas, equal in vo- 

 lume to the i»idrogen, that the potash was capubie of evolv- 

 ing by its contact with water: and always too, on treating 

 potiissium with sulphuretted hidrogen gas, we have ob- 

 tained as much hidrogen gas, as the pofassiu.n would have 

 yielded with water. 



•* We affirm anew, that these results are certain. 



Potassium «* Mr. Davy considers it as probable, that, on heating po- 



•ulphur. taasium with sulphur, a portion of potassium remains in the 



centre of the sulphuret of this metal. It but little sulphur 



be employed, this does not take place: still less then can it 



when a great deal is used, as is done by Mr* Davy. 



••Mr, 



