Dlfcovery of a new Eat'th. 359 



ExpL-riment 2. The fluid feparated from the filex was precipitated by the carbonate of 

 potafli of commerce; the precipitate coUefted and drained was treated with a folution of 

 cauftic potafli. The greateft part of the matter was diflblved ; but there remained a cer- 

 tain quantity of earth which v/as not taken up. This being feparated, vvalhed, and dried 

 by ignition, was of a brown greyifli colour ; it weighed nine parts. In thefe nine parts it 

 is that our new earth is contained. We fliall fpealc of it again in the fubfequcnt part of 

 this Memoir. 



Experhnent 3. The alkaline folution of the foregoing experiment was fuper-faturatcd 

 with muriatic acid, until a perfeft folution took place, and thisw.^s again precipitated by 

 the carbonate of potafli of commerce : the depofition, wafhed and dried by a red heat, 

 weighed 21 parts. 



This fubflance appeared to me at that time to be pure alumine. We fliall fee wh.it 

 conclufion ought to be made, after examining the properties of the new earth which I 

 Iiave announced. 



Experiment 4. The nine parts in Experiment 2. remaining after the adlion of the potafli, 

 and in which I announced the exiftence of a new earth, were diflblved in the nitric acid } 

 the folution was evaporated to drynefs, and the refidue again diflblved in water. The fo- 

 lution of this fubfliance having aflumed a reddifli yellow colour, which indicated the pre- 

 fence of iron, a folution of the hydro-fulphuret of potafli was mixed with it ; a black volu- 

 minous precipitate was formed ; the fluid was heated in order to favour the union of the 

 parts, after which the fluid was decanted clear and colourlefs. The black precipitate by 

 calcination became of a red brown colour, and weighed one part. When diflblved in the 

 muriatic acid, and the folution evaporated to drynefs, it afforded a beautiful blue when an 

 atom of the matter was thrown into a folution of the PruflTiate of potafli : it was therefore 

 the oxide of iron. 



The fluid from which this exide had been feparated was again evaporated to drynefs ; 

 and though at firfl: it had no colour, it ncverthelefs became red towards the end of the pro- 

 cefs, and the refidue preferved that colour. This refidue having been left for 24 hours in 

 a capfule, became reduced into a kind of gelatinous fluid, of a yellowifli red colour : cold 

 water poured thereon diflblved the whole mafs ; but the folution was red and turbid : by 

 «xpofure on the heated fand-bath, red flocks were feparated, and the fluid became as clear 

 as water. Thefe flocks, carefully feparated, waflied and dried, weighed half a part : it 

 was alfo the oxide of iron j which, with the part before obtained by means of the hydro- 

 fulphuret of potafli, makes one part and a half of that fubfl:ance. 



Experiment 5. The earth being thus perfedly deprived of the oxide of iron, I feparated 

 It from the nitric acid by means of the common carbonate of potafli ; and I obtained 12 

 parts of a white earth, foft beneath the fingers, and foluble in acids with eflbrvefcence. 



We fee that this earth, in its feparation from the nitric acid, did abforb four parts and a 

 half of carbonic acid i fince out of nine which were fubjefted to experiment, one and a 

 half of the oxide of iron were obtained ; which leaves 7,5 for the earth contained in the 

 J 2 parts of carbonate lafl; precipitated. 



3 A 4 StSHsn 



