52 Rock, Spring, and Sea-Salt. 
likewife the Appearance of regular Hexa¬ 
gons, as in Plate I. N° I. /. 
I have examined various Species of thefe 
Salts from different Parts of the World, and 
particularly feveral brought from Egypt? 
Hungary, Germany, &c. by my worthy and 
ingenious Friend Dr. Richard Pocock, Arch¬ 
deacon of Dublin, and F. R. S. which, 
tho’ red, brown, white, &c. and feemingly 
of very different Contexture, fome appear¬ 
ing fibrous, others fparry, talcky, &c. yet, 
when diffolved and examined, much the 
greateft Part of the regular Bodies produced 
in them all were of the fame general Fi¬ 
gure, i. e. hollow Pyramids j with little 
farther Difference, than that fome were 
more tranfparent and iharper at the Top 
than others. It may therefore realonably 
be concluded, that an hollow Pyramid, 
either pointed or flat, is the general Figure 
of all Fojjile, Sea, and Spring- Salts, when 
after being diffolved, arid a final! Degree 
of Fleat given, their Particles are brought 
together, and unite again according to the 
Order and* Difpofition of Nature r which 
hollow Pyramid is competed of minute 
Cubes moR regukrly and wonderfully com- 
Fined H And this has- been demonflrated 
even- 
Dr. Brovjnrigg obferves, in bis very curious Treatife 
of the Art cf making Cdmmon Salt, p. 67, That when by 
a- very gentle Exhalation of Water from eomraon Salt, it* 
