3 t2 Of Salts . 
bend. Its whole furface is adorned with little'channels 
and interjacent ridges, which run the whole length of 
the beard, and are ftreight where the beard is not twilled, 
and wreathed where it is, being thickly fet with fmall 
bridles; in the wreathed part was two very confpicuous 
channels, which feemed to divide the wreathed cylinder 
into two parts, a bigger and a lefs, the biggefl at the 
convex fide of the knee; thefe clefts are filled with a 
kind of fpongy fubflance, very confpicuous near the 
knee. 
This odly conflituted vegetable is fometimes ufed, as 
an hygrometer m , to difcover the various conflitutions in 
the moiflure and drynefs of the air 5 and this it does to 
admiration. 
Of falts. 
U NDER the denomination of fait, is to be under¬ 
flood mofl of that which gives folidity to bodies, 
is difiolvable in water, and affects the tafle with a peculiar 
pungency. There are three diflinCt forts which generally 
pais under this name, the fixed, volatile, and the effen- 
tial: the fixed is what remains after calcination, and is 
procured by diffolving the faline parts pf the afhes in hot 
water, and evaporating it until the fait is left dry at the 
bottom; for that will not rife in vapours. The volatile 
is what eafily paffes over the helm, as the falts of animals. 
The effential fait is that which is obtained by chrifliliza- 
tion from the juices of plants, and is of a nature between 
the other two, and may mcft properly be termed effential, 
having no force ufed in its production. 
If 
m If the reader is defirous of one of thefe Hygrometers, he 
may be furnilhed with them at my fhop, &c. 
