108 Biography of Berzelius. 
similarity in chemical characters. It has frequently. been seen, 
that works in which a theoretical principle has been jae! fol- 
lowed throughout, do not so well fulfill their principal objec 
In the organic part of this work, Berzelius has declared hiraself 
against the so-called substitution theory, and the law of types. 
He assumes, on the contrary, that conjugate compounds exist in 
organic bodies, in which, for instance, acids are united with com- 
pound radicals, or with their oxyds, chlor ids, &c., in such a way 
that the acid is not saturated, but is still capable of combining 
with bases without separation of the associated substance,—the 
conjunct,—which enters with the acid as a constitutent of the 
salt. When an acid has entered into such a conjugate combina- 
pe it has generally acquired such altered characters, that neither 
the acid nor its salts are similar to the free acid and its salts. 
When hydrogen is replaced in an organic substance by chlorine, 
or another halogen, this generally takes place in the conjunct and 
not in the acid, “and the former does not on this account cease to 
play its former part, of modifying the character of the salts into 
which it enters, with its acids, more or less, and according as its 
composition is altered by substitution. 
It has been asserted that the replacement of hydrogen by chlo- 
rine, in organic compounds, was not to be explained at all in ac- 
cordance with the electro- chemical views of Berzelius, and that 
consequently these views were incorrect. But when such a sub- 
stitution takes place, it is, as already mentioned, generally only 
in the compound radical,—that is, the conjunct, ‘and a new radi- 
eal is thus formed, in which chlorine may ee occupy ee 
place of hydrogen, but cannot play the same part as it did. 
stitution of elements may therefore be very afaewrily ms 
plained, according to the principles of Berzelins; and if his theo- 
ry be impartia ally co compared with the others which have been put 
forward in such number in organic chemistry, the inference will 
be, that in the present state of the science it is ina position to 
explain the facts more satisfactorily than any othe 
On looking carefully through the various editions of this work, 
it is impossible not to regard it with admiration. It is not only 
the clear and comprehensive description, which attracts, —the 
pis impartial criticism, which compels men of opposite ce 
on to appreciate justly,—or the great minuteness which has 
left unnoticed . single fact, paca trifling, if it was of any in- 
uence—but it is also the enormous industry which must create 
astonishment. gn se seatibie man who had done nothing more 
than publish this <ilet t work, in so many editions, each of 
