[ * 47 . ] 
Other Salt. I thought there was no bfecter 'of 
proceeding in this Inquiry, than by Cryftallization j 
becaufe it is univerfally allowed, that Salts in Cryftal- 
Ijzing conftantly retain one certain and determinate 
Figure ; Sea-Salt concreting into Cubes, Vitriolic 
Salt into Rhomboidal Parallelepipeds, Alom into 
O^tsedrons, and Nitre into Redangular Priftns on 
Hexagonal Safes. I imagined, that if the Salt of 
Vefuvtus happened to contain any Particles of the 
Salts above-mentioned, it would difcOver them after 
Cryftallization. This way of Reafoning was con- 
firm’d by Experiment : For the Vefuvmn Salt,, in 
Cryftallizing, left on the Sides of the VefTcls fmall 
Parcels of cryftallized Salts, which, oblerved through 
a Microfcope, rcfembled a Tree with its Branches, 
on the Ends of which there appeared feveral Pyramids 
of an irregular Figure, but very (harp-pointed ; and 
between the Branches there were interfperfed in 
fome Places a Group ofPrifms, in others fomc fmall 
Cubes : Whence I inferred, that the aforefaid Salt 
was Ammoniacal, and indeed a genuine and effica- 
cious Salt Ammoniac, with infcnfible Portions of 
Nitre and Sea-Salt. Which coincides with the Sen- 
timents of the Royal Academy of in 1705 ; 
with thofc of Thomas Cornelius in his Trogymnafma 
de Senjibus'y oi T>ominicus Gulielmini in hisTreatife 
de Salibus 5 of Dr. Boerhaave in his Chemiftry, and 
many other Writers. 
Experiment IX. 
In order to be convinced whether this Salt was 
really Ammoniacal, and of the Nature of neutral 
Salts, I mixed it with Spirit of Vitriol, and Spirit 
I i 2 of 
