Chemical Notation of Laurent and Gerhardt. 367 
3Mg O, Si0,+Al, O0,,SiO,+2(Mg 0, 4H, 0). 
This we write, 
Si O, (Al?3 Mgs H3), 
and this formula reminds us at once that chlorite belongs to the 
silicates of the form SiO, (M,),* for 3+4+4=4. 
he advantage of our notation consists then principally in this, 
that it expresses all the salts of the same genus in the same man- 
her; each symbol appears but once in a formula. Consequently 
we denote similar compounds in a similar manner 
_ In the notation of organic substances, we take their volumes 
into consideration, when they are bodies which are volatile with- 
out decomposition. We denote these always by the same num- 
rt of volumes, and the non-volatile compounds derived from 
them by similar formulas. Thus for the monobasic acids, we 
take as an equivalent the quantity which contains (H) one equiv- 
alent of basic hydrogen; this corresponds to two volumes o 
vapor. The derivatives (non binémes,) which do not perform 
the functions of salts, are represented by the same number of 
volumes ; in case these derivatives are fixed, we take as an equiv- 
alent the quantity produced by one equivalent or yielding one 
equivalent, of the monobasic acid. For example, 
Berzelian notation. "H_0.(H) 
Acetic acid 2 Se On C, 3Ve 
Acetate of potash, C,H.O,, KO 0, H,0,(K) 
Ferric acetate, . 3C,H,O,, Fe,0O, C,H,0,(Fe#) 
Chloracetic acid, . ©,0,,C,Cl,,H,O C,C1,0,(H) 
ua of 2 - ,0,,C,C1,, KO 0,1,0,(K) 
Ferric chloracetate, 3(C,0,,C,Cl,),Fe,0, C,Cl,0,(Fe?) 
Mend, gs. GAO C,H,O 
Aldehyde, . . . C,H,0, C,H,0 
C,H, 
Olefiant gas, . . ‘ CH, 
The bibasic acids not being volatile without decomposition, the 
law of volumes cannot be applied to them directly, but these 
acids give by decomposition, volatile anhydrids. We re then 
as the formula the quantity which yields two volumes of an an- 
hydrid. These acids are therefore represented with two equiva- 
lents of basic hydrogen (H, ). Examples. 
Berzelian notation. notati 
Stale st yout, COED. C.0.(K:) 
ate of potash, C,O, $ 
Binoxalate Sf potiah, 6.0,, KO+C,9,, H,0O C,0,(HK) 
deaeee << : C,0,,K0+3(C,0,,H,0) C,0,(H} Ky) 
3 s . 
* We write silica SiO; (SiO, 2Mz O=Si 0, (M¢).) 
