206 ESSAYS anp OBSERVATIONS . 
which by: its fmell and properties fhewed 
itfelf to be flightly alkaline. He does not 
tell us the weight of the ofteocolla remain- 
ing in the retort, and only fays, that it 
was converted into quick-lime; but,as no 
calcarious earth can be converted into 
quick-lime, or bear the heat. which he ap-- 
plied without lofing above a third of its 
weight, we may fafely conclude, that the 
lofs in his experiment was proportional, 
and proceeded chiefly from the diffipation 
_of fixed air. i 
ACcoRDING to our theory, the relation 
of the calcarious earth to air and water 
appeared to agree with the relation of the 
fame earth to the vitriolic and vegetable 
acids. As chalk for inftance has a ftrong- 
er attraction for the vitriolic than for the 
vegetable acid, and is diflolved with more 
difficulty when combined with the firft, 
than when joined.to the fecond: So it al- 
fo attracts air more ftrongly than water, 
and is diflolved with more difficulty when 
' faturated with air than when compound- 
ed with water only. 
