ORDER III. PRISMATIC BORACIC-ACID. 25 



The liquid Sulphuric-acid contains at least 18-5 per cent, 

 of water. If it contains 37 per cent, it possesses the pro- 

 perty of crystallising at a temperature of 4 5 centigr., 

 about 40 Fahr. The crystalline forms quoted are six-sided 

 prisms terminated by six-sided pyramids, of which as yet 

 neither the system nor the angles have been determined. 



2. The liquid Sulphuric-acid occurs in the neighbour, 

 hood of several volcanoes, as Mount Etna, and in great 

 quantities in the island of Java, &c. ; it is found besides 

 in caves in several places in Italy, and at Aix in Savoy. 

 Sulphuric-acid is also formed by the decomposition of seve- 

 ral species of the order Pyrites. 



GENUS IV. BORACIC-ACID. 

 1. PRISMATIC BORACIC-ACID. 



Sassoline or Native Boracic Acid. JAM. Syst. Vol. III. 

 p. 48. Scaly Boracic Acid. Man. p. 5. Sassolin. HAUSM. 

 III. S. 803. Boraxsaure. LEONH. S. 113. Acide bo- 

 racique. HAUY. Tabl. comp. p. 2. Traite', 2de Ed. T. I. 

 p. 297. 



Fundamental form. Scalene four-sided pyramid. 

 Vol. I. Fig. 9. Determinable forms unknown. 



Lustre pearly. Colour greyish- and yellowish- 

 white. Streak white. Feebly translucent. 



Sp. Gr. = 1480. BERZ. Taste acidulous, after- 

 wards bitter and cooling, lastly sweetish. 



Compound Varieties. Loose scaly particles, crys- 

 talline grains, sometimes aggregated in the form of 

 crusts. 



OBSERVATIONS. 



I. The prismatic form of the six-sided tabular crystals 



