ao 
[ Wl 
XXXII. An Attempt to determine the definite and simple Pro- 
portions, in which the constituent Parts of unorganic Sub- 
stances are uniled with each other. By JacoB BER2ELIUS, 
Professor of Medicine and Pharmacy, and M.R.A. Stock» 
holm. 
[Continued from p. 101.] 
II. Laws FoR THE FORMATION OF SUBSALTS, 
Every chemist knows what is understood by neutral salts; 
but it is by no means easy to give a good definition of what is 
properly vewtral. If we take that condition of alkaline salts, in 
which both the acid and the base are perfectly indifferent, so as 
to produce no reaction on vegetable colours, as an example of 
neutrality, it seems that we ought to’consider those salts only as 
neutral, in which the same quantity of oxygen in the base com- . 
bines with the aeid, as in these alkaline salts, and which in double 
decompositions would set neither acid nor base at liberty. Davy, 
in his Essay on Electricity as a chemical agent, calls every com- 
bination neutral, in which the original electric reactions have 
ceased. This is in fact the only correct and scientific conception 
of a neutral combination ; but it is only relative. For, according 
to this determination, the oxygen in the protoxide of lead, for ex- 
ample, must be neutralised; it no longer acts on the greater 
number of bodies as a [negatively] electrical substance, yet still 
retains the same relation to more combustible bodies, for in- 
stance, to potassium. Exactly the same is true of neutral salts. 
While potass and soda saturate a quantity of sulphuric acid, 
which contains three times as much oxygen as themselves, so 
completely, that the acid loses its powers, this is by no means the 
case with the protoxide of zinc, the oxide of iron, alumina, or 
zirconia. The attractions of these bases being extremely weak, 
every substance, which comes into contact with the salts, makes 
an effort to deprive them of a part of the acid: hence the action 
of the acid is still perceptible, and the salts appear not to be neu- 
tral, although they are the most neutral combinations of which 
the bases are susceptible. We are accustomed to call them szper- 
salts, hecause the acid possesses the strongest powers, and con- 
sequently exhibits its effects most distinctly on the taste, and on 
vegetable colours. -~But when we consider the combinations of 
‘the weaker acids with the stronger bases, we find, that the base 
always exhibits its powers the most obviously. Thus, for ex- 
ample, the common deliquescent carbonated potass is sometimes 
called a subsalt ; although the carbonic acid is united in it with 
the same quantity of oxygen, as in the carbonate of baryta or of 
lime, and these three salts are consequently in the same com- 
Vol. 43,No. 191. March 1814, + JL parative 
