PHILOSOPHICAL 
TRANSACTION S. 
I. A Synoptic Scale of Chemical Equivalents. By William Hyde 
Wollaston, M. D. Sec. R. S. 
Read November 4, 1813. 
W HEN the nature of any saline compound is proposed as the 
subject of inquiry to an analytic chemist, the questions that 
occur for his consideration are so varied and so numerous, 
that he will seldom be disposed to undertake a series of original 
experiments for the purpose of satisfying his inquiries, so 
long as he can rely upon the accuracy of those results that 
have been obtained by the labour of others, who have pre- 
ceded him in this field of patient investigation. 
If, for instance, the salt under examination be the common 
blue vitriol, or crystallized sulphate of copper, the first obvi- 
ous questions are, (1) How much sulphuric acid does it con- 
tain ? (2) How much oxide of copper? (3) How much water? 
He may not be satisfied with these first steps in the analysis, 
but may desire to know further the quantities (4) of sulphur, 
(5) of copper, (6) of oxygen, (7) of hydrogen. As means 
of gaining this information, he naturally considers the quan- 
V MDCCCXIV. B 
