748 © HISTORY of the SOCIETY. 
Dr Hort likewife read fome obfervations on the native car- 
bonate of barytes or aérated terra ponderofa of Dr WiTHER- 
ING. The two following deferve moft to be noticed. 
AFTER quoting the words of Doétors WiTHERING and - 
PriestLey, M. Sace, Fourcroy, Pexnyetier, and of Mr 
Wepcewoop junior, to fhow, that they all agree in afferting, 
that the fixed air cannot be expelled by heat from this fubftance, 
he mentioned feveral experiments, in which heat alone deprived 
it of its carbonic acid, rendered the earth cauftic, and caufed a 
‘lofs of weight equal to 23 per cent. He defcribed the qualities 
of the calcined barytic fpar. : 
Tue fecond obfervation of importance relates to the cryftal-— 
lization of the pure barytes, which fubftance he has obtained 
in beautiful and regular cryftals ; the more obvious, as well as 
chemical properties of which he at full length recounted. 
TABLES fhewing the attraction of and for StRONTITES. 
TAB. I. Ey wes iy Cie 
StronTiTEs, | Sulphuric Acid. Oxalic. Yartarous.  Fluorte. Nitric. 
Sulphuric Acid.| Barytes Barytes Lime Lime | Barytes 
Oxalic Strontités Lime ¢ Barytes Barytes . Potafs 
Tartarous Potafs Strontites Strontites Strontites Soda 
Fluoric Soda Potafs Potafs Potafs Strontites 
Nitric Lime Soda Soda Soda Lime 
Muriatic : 
Paeguenie Muriatic. Arfenic. Phoafpborsc. Boratic. Garboute, 
‘Age Barytes Lime Lime Lime Lime 
cetous 
‘Arkeme Potafs Barytes Barytes Barytes f Barytes 
Boke Soda Strontites Strontites  Strontites Strontites 
Pipi Stiontit Potafi Potafi Potafi Potafs 
Cascee ti ontites otafs otafs ‘otafs ota: 
Lime Soda Soda Soda Soda 
The Brackets in Tab. II. denote, that it has not been difcovered how Strontites ftands 
with regard to Barytes and Lime, in its attraClion for the acid below which this mark 
is made, 
END OF THE HISTORY? 
