244 & r ‘ Watt on the Ufe of Symbols . 
imaginary, to the fubftances which they are 
employed to reprefent- That many of them are 
entirely arbitrary, is commonly fuppofed by 
thofe, whofe knowledge of chemical authors is 
only flight and fuperficialj but the enthufiafm 
of a few, whofe reading has been more extenfive, 
fuggefts a different idea- Every character is, by 
thefe, conceived to convey an accurate defcription 
of the qualities of the fubffance, which it repre- 
fents. It is hardly neceffary to obferve, that 
this opinion is not indireftly fupported by 
Boerhaave , and his commentator Shaw*: and Dr. 
Price f in his account of his extraordinary expe¬ 
riments on mercury, filver and gold, afferts, that 
the ancient chemifts either knew or believed, that 
the imperfect metals had a faline principle, which 
they denoted by a crofs attached to their cha¬ 
racters. It is impoffible, perhaps, to advance 
very far in our enquiries into this fubjeft ; yet 
fome little light may be thrown upon it, by a 
due attention to thofe characters, which are above 
alluded to, thofe by which the metals are re- 
prefented. And firft, it cannot but appear very 
ftriking, that the fymbols employed to reprefent 
the feven metals, which alone were known in 
the earlier ages, are the fame, as thofe which 
were applied by the firft aftronomers, to denote 
the feven planets. The chemifts have, in gene- 
* Shaves Boerhaave, vol. I, p. 68. 
■J- Price's "Experiments on Mercury, Sec. Preface, p. ir. 
ral. 
