of Chemical Equivalents. 3 
to determine the proportions in which the different known 
chemical bodies unite with each other, and to express these 
proportions in such terms that the same substance shall always 
be represented by the same number. 
It is to Richter that we are originally indebted for this 
mode of expression, and for having first observed that law of 
permanent proportions on which the possibility of this numerical 
representation is founded. The proportions assigned to vari- 
ous salts by his predecessors Bergman, Wenzel, Kirwan, 
were incompatible with this mode of notation. If we turn to 
Bergman's treatise De Analysi Aquarurn^ we find it stated 
that in sulphate of potash 40 of acid are combined with 52 of 
potash, or that 100 of sulphuric acid take 130 of potash. In 
muriate of potash, 61 of the alkali are said to be combined 
with 31 of acid, which is in the proportion of 130 to 66 . So 
that the same quantity of potash that is saturated by 100 sul- 
phuric acid, requires of muriatic 66 . 
But if we make a similar estimate by means of lime, since 
sulphate of lime is said to contain 46 acid combined with 32 
lime, 100 of acid would require 69,5. And in muriate of lime, 
since 44 of lime are said to be combined with 31 of acid, thence 
69,3 of lime would require 49. So that in this instance it 
would appear that the equivalent to 100 sulphuric acid, instead 
of being 66 muriatic, is 49 ; which, if true, would defeat our 
attempts to express the same body always by the same 
number. 
In comparing the analyses of Wenzel with each other, we 
find the same inconsistency. If we select sulphate of ammo- 
nia, and muriate of ammonia, we obtain 67,3 as the equivalent 
of muriatic acid. But by comparison of sulphate of magnesia 
B 3 
