446 
SECOND REPORT—1832. 
This notation possesses the two great requisites clearness 
and brevity , and it would he very difficult to devise any other 
system which should possess them in an equal degree. It has 
been objected, however, that it has appropriated a mode of no¬ 
tation already employed in algebra with a very different signi¬ 
fication ; and it would certainly have been very desirable if 
such an appropriation could have been avoided. 
In the simple cases given above as illustrations, it is not very 
much longer to write N + 2 C + O for cyanic acid, which is 
algebraically correct, than to express it by N C 2 0; but if we 
go to more complex cases, we shall find pure algebraic notation 
become so cumbersome as to impair very materially both the 
requisites of a chemical notation: thus cyanate of ammonia 
N C 2 O + N H 3 + H represented algebraically, is (N + 2 C + O) 
+ (N + 3H)+(0 + H), a form of notation which is much 
longer: but if we take an extreme case like the double ferro- 
cyanides formed by Mosander, we shall see how the clearness 
as well as the brevity of the notation will be impaired. One of 
these salts is composed of an atom of ferrocyanide of potassium 
united to an atom of ferrocyanide of magnesium thus expressed, 
(FeNC 2 +2KN C 2 ) + (Fe N C 2 + 2 Mg N C 2 ), which, with 
all the algebraical signs interposed, becomes 
((Fe+N+2C)+2 (K+N+2C)) + ((Fe+N+2C) + 2 (Mg+N+2C)) 
While it is very desirable therefore to express the composition 
of chemical compounds by a notation as nearly algebraical as 
possible, it would obviously be to sacrifice both brevity and 
clearness to insert all the algebraical signs in all chemical 
formulae. 
Arbitrary Symbols. —For the purpose of simplifying notation, 
several arbitrary signs have been introduced by Berzelius. 
Thus the dot (*) over a letter denotes an atom of oxygen, the 
comma (’) an atom of sulphur, a horizontal line (“) selenium, 
a cross ( + ) tellurium. A longer line (“) over a letter denotes 
that it is an organic acid. Thus, 
• ••• • ••• 
Oxymolybdate of potash = K Mo or K + Mo 
9 555 9 9)9 
Sulphomolybdate of potash = K Mo or K-f Mo 
Selenomolybdate of potash 
Telluromolybdate of potash 
= K Mo or K+Mo 
++++ + +++ 
= K Mo or K-f-Mo 
T, Tartaric acid ; A, Acetic acid, &c. 
Abbreviations also are employed : thus Cy is cyanogen, = N + 2 C ; 
Bz is benzule = (14 C + 10 H + 2 O). 
