Biography of Berzelius. 177 
of hydrogen must be able to replace one atom of oxygen or 
sulphur. 
Even if it does sometimes happen that we do not find conclusions 
of this kind confirmed by experiment, if in the replacement of one 
body by another in compounds, an element, as for instance potas- 
sium, may be replaced by a compound radical such as ammonium, 
still it is not admissible to assume that such substitutions as may 
be theoretically inferred from the similarity in atomic weight, or 
atomic volume, really do take place, without the authority of re- 
peated experiment. It is certainly convenient to regard equiva- 
lent and atom as synonymous terms, although not truly appropriate 
in a scientific view. 
For the purpose of expressing the proportions in which bodies 
_ combine chemically, Berzelius, so early as the year 1815, employed 
certain signs as symbols for the different elements. Such signs 
were employed long before this in chemistry, or rather alchemy, 
although they were then of little value. These symbols undoubt- 
edly owed their origin to the mysterious relation between the plan- 
ets and metals, as assumed by the alchemists, and the pleasure 
which they took in expressing themselves in a manner unintelligi- 
ble to the people. Berzelius would not adopt the old symbols, not 
only because they were, in fact, destitute of all significance, but 
likewise because it is certainly easier to write the abbreviation of a 
word than to draw a figure. 'The symbols of Berzelius, however, 
Serve to express the chemical combining proportions, and the 
chemical formule furnish a means of representing the numerical 
results of an analysis with all the simplicity of an algebraical 
formula. 
employ it ; and this renders it the more remarkable, that the op- 
position made to this innovation was at first so considerable. A 
French philosopher exchanged the symbols proposed by Berzelius, 
for the initial letters of the French names for the elements. But 
it was in England that the greatest opposition was made to the 
adoption of the chemical formule of Berzelius. Even so late as 
1822, an English chemist, speaking of them, said, ‘“ they are cal- 
culated more to produce misunderstanding and mystification than 
clearness, since they are of a nature totally different from algebra- 
ical formule ; it would be easier to express oneself in ordinary 
words than with these symbols, which only make a kind 
mathematical parade.” Berzelius replied to the partly rude and 
uncourteous objections with dispassionate clearness and com- 
posure. Who would now consider it possible to dispense with 
- the use of these “ abominable symbols” of Berzelius, as they were 
Seconp Series, Vol. XVI, No. 47.—Sept. 1853. POTS a 
