Dr. Wollaston's Synoptic Scale 
never admit of any argument that will be deemed conclusive 
by all parties. 
With the same latitude of interpretation may be understood 
muriate of potash or of soda in the scale of equivalents ; and 
the relative weights of mere potash or soda may, perhaps, be 
determined better by means of these compounds than by any 
other, because they are not liable to be superacid, and are not 
decbmposed by heat. 
If to a quantity of muriatic acid, which, by previous trial, I 
know would dissolve lOo carbonate of lime, I add loo grains 
of crystalfized carbonate of potash, and after the addition find 
that it will dissolve only 49,8 of carbonate of lime ; I hence 
infer that 100 of this carbonate is equivalent to 50,2 carbo- 
nate of lime, and consequently that 125.5 is the equivalent to 
63 in the table. 
Next, if I combine 125,5 of crystallized carbonate of potash 
with an excess of muriatic acid, and evaporate to dryness, I 
expel the whole of the water with all redundant acid, and 
I find 93,2 of neutral salt; and whether I call it muriate of 
potash, or chlorid of potassium, or by any other name, with 
any other views, I may deduct 34,1 as dry muriatic acid, 
(whether real or imaginary*) and infer the equivalent for pot- 
ash to be 59,1, even though there should, in fact, be only 49,1 
of potassium present, requiring lO'j'* of oxygen to convert it 
into potash. 
• Its separate existence is certainly imaginary, for it can no more be obtained un- 
combined than dry sulphuric acid, or dry nitric acid. 
f If all the steps in the scries, by which the number 49,1 is inferred, be correct, 
this should be exactly 10,00 without any fraction; and the proportion assigned to 
muriate of potash by Berzelius is sufficiently near, to shew that there can be no' 
considerable error. 83,02 : 16,98 : : 49,1 : 10,04. 
