360 Propertks and Habitudes of ihe tuiv Earth difcovered in the Beryf, 



SeSion III. Expofttion of the Properties of the new Earth contained in the Beryl, 



Experiment i. The 12 parts of earth united with carbonic acid, as before mentioned^ 

 were put into fulphuric acid, which diflblved them completely with efFervefcence. The 

 folution had a very facchavine tafle at firft, and aftringent at laft. The folution left till 

 the following day afforded irregular cryllals, very folid and Hiccharine like the folution. 

 which afforded tliem. 



Experiment 2. Thefe cryflals were again diffolved in water ; the folution rrixed with ful- 

 phate of potafli did not afford alum either immediately nor by evaporation, as happens in- 

 the alumine when combined with the fulphuric acid. Each of thefe falts cryflallizes fe- 

 jsafately, without contraifling any union. 



I repeated tliis operation five times in fucceffion, with different dofes of fulphate of poN 

 afh, without obtaining more fuccefs than at firft. At laft, to convince myfclf of the differ- 

 ence between this earth and alumine, I took equal quantities of the one and the other ; 

 and after having diffolved them in the fulphuric acid, I mixed them with Kke quantities of- 

 fulphate of potafli. I conftantly obtained oftahedral alum with the aiumine ; but the 

 earth of the beryl afforded only an irregular fait. 



Thefe differences firft difcovered between the two earths, induced rae to feek for others,. 

 by comparing them in a greater number of points. ' 



, SeBion IF. Campari/on of ihe Properties of the Earth of Beryl uith thofe of Aiumine. 



Experiment I. For this purpofc, I feparately diffolved equal quantities of alumine and of 

 tlie earth of beryl in nitric acid, to perfect faturation. 



The fait which atofe from the combination of the earth of beryl' with the nitric acid, did: 

 not appear fufccptible of cryftallization ; it ftrongly retains moifture ; by deficcation it- 

 becomes converted into a kind of ductile pafte, which, when expofed to the air, power- 

 fully attradls moifture. Its tafte is at firft very fweet, and afterwards aftringent. 



Experiment 2. The nitrate of alumine likewife cryftallizes with confiderable difficulty 5 

 but it does not attra£l moifture fo ftrongly. Its tafte is not faceharine, like that of tha 

 nitrate formed with the earth of beryl. 



I made the following comparative effays of the folutions of thefe two falts, uGng equal 

 quantities of each. 



I. The nitrate of alumine, mixed with a folution of nut-galls in alcohol, afforded no pre- 

 cipitate. The fluid fimply acquired a flight greenifti colour, and loft fomewhat of its 

 tranfparence ; however, at the expiration of fome hours, the fluid, having been diluted 

 with water, let fall a greyifti precipitate. — 2. The fait of the earth of beryl, mixed with 

 the fame re-agent, immediately afforded a depofition in flocks of a yellow brown colour. 



3. The nitrate of alumine, mixed with the oxalate of potafti, immediately afforded a pre- 

 cipitate in the form of very abundant white flocks, which fubfided to the lower part of the 

 veflel, and left the fuperior fluid perfedly clear.— 4. The fait of the earth of beryl, with- 

 the fame re-agent, did not afford the flighteft appearance of a precipitate, eycn after feve- 

 i*i days. 



5. The 



