Definite Proportions. 5 
equivalent quantities. But instead of 74 grains of salt, 
which is the number on the scale belonging to muriate of 
soda, we happen, in a certain case, to have 100 grains; and, 
number 100 stand against muriate of soda, the required 
quantities of all the other bodies will be indicated by the 
numbers standing opposite to them on the slide. _ This result 
depends on the principle that, if we move the slide either 
way, and ever so much, the numbers that stand opposite to 
the various bodies, will remain constantly in the same ratio 
to one another. Thus, before moving the slide, 20 stood 
opposite to sulphur, and 10 opposite to oxygen ; now 100 
hended b 
rule. . ae : 
After the constancy of the proportions in which bodies en- 
Proposition 4. When two substances, A and B, unite so 
as to form several different compounds, let the quantity of A 
remain the same in them all, then the respective quantities of 
B will be such, that all the higher proporti 
pounds, by combining with different quantities of oxygen ; 
bonic acid as the neutral carbonates. Carbonic oxide has 
just half as much oxygen as carbonic acid. A similar defi- 
* It is commonly said that all the higher proportions of B are simple mul- 
tiples of the lowest. But this is not 8 true: thus in the example which 
follows, the third proportion (5) is obviously not a multiple of 2. 
He 
