of Alkalies and Earths. 349 



that they extra6led from fix grammes of this fait one gramuie 

 of magnefia. 



To repeat this experiment, the hyper- oxygenated muriate 

 of foda was made by faturating with oxygenated muriatic gas 

 a folution of pure carbonate of foda. When this fait was 

 formed, it was evaporated to drvnefs in a porcelain capfule ; 

 and 6 grammes of it in this Itate were put into a platina cru- 

 cible, when fufrd phofphoric acid was added in fmall por- 

 tions. The mixture immediately became yellow, and a great 

 deal of oxvgenatcd muriatic acid was difengaged, as was the 

 cafe in the experiments made with oxygenated muriate of 

 potafli. I continued to add phofphoric acid till nothing more 

 was difengaged ; upon which, a ftrong heat being applied, 

 the whole mafs became liquid. After cooling there was 

 found a vitreous matter, brittle, flightly deliquefcent, and 

 wholly foluble in water. When the liquor had become verv 

 clear, an attempt was made to precipitate from it the mair- 

 nefia, by the help of potafli; but having obtained not a fingle 

 atom of precipitate, the experiment was repeated feveral times, 

 but always without fuccefs. From what has been faid, it is 

 evident that the magn(;fia obtained by the above authors can 

 not have arifen but from the foda which they employed; for 

 it is kno'vVji that foda is very often accompanied with mag- 

 nefia. In this experiment, as in the fifth, the platina is 

 ftrongly attacked. In two trials I had a refiduum of eight 

 centigrammes of this metal. O 



£.v/). VII. Nitrate of foda treated by the phofphoric acid 

 gave to the above authors magnefia. I repeated this experi- 

 ment four times without obtaining; the fame refult. I varied, 

 but in vain, the doles of the fait and the acid, as well as the 

 mode of operation; but by employing as much as 30 

 grammes at a time of nitrate of foda, and 10 of acid, I ob- 

 tained only a blackiih refiduum weighing four centigrammes, 

 which was found to be filex coloured by charcoal. Thole 

 who recoUeft the exiftcnce of this earth in the phofphoric 

 acid difcovered by C. Vauqueiia, will be able to account for 

 the filcx found in this experiment. 



I muft inform thofe who may wiOi to repeat this experi- 

 ment, that they mud not eniphn' phofphorous acid for phof- 

 phoric acid ; for when the former is employed, and poured 

 over the red and fufcd nitrate, a very flrou'r deflai; /.tion is 

 produced, the matter is thrown frem the crucible, and fpeed- 

 ily burns every thing that it meets with. This obfervatioa 

 ought to be recollerted in regard to the Experiments 5 and 6. 



Exp. V'lll. In this eighth experiment, when potalli was 

 healed wiili charcoal, and when the capfule coiiiaiuing the 



mtxlurtt 



