System of Chemical Notation, 133 



cept in hydrogen, where H is the product of 1 and >/«), it is 

 obvious that twice the index of a in a unit symbol is the number 

 of perissad atoms in the molecule. From this we can easily 

 frame rules for translation. 



1st. To translate from the ordinary notation into that of the 

 calculus. 



Let p be the number of perissad atoms in the molecule, then 



^ is the index of a in the unit symbol ; then change the symbols 



for the atoms (exclusive of H) into the symbols for the corre- 

 sponding prime factors (O m into f m , Cl re into x n , O into K r &c). 



Examples. 



Mercuric perchlorate, HgCl 2 O 8 . 



p = 2, therefore index of a = l, Symbol uS^' f 8 . 



Glycerine, C 3 H 8 3 . 



p = 8, index of a = 4, Symbol a 4 k 3 f 3 . 



Cyanide of kakodyl, AsNC 3 H 6 . 

 p = 8, index of a = 4, Symbol u 4 pvfc 3 . 



Sulphuric anhydride, SO 3 . 

 p = 0, index of a = 0, Symbol Of; 3 . 



Nitric oxide, NO. 

 p = l, index of a = J, Symbol azj/f*. 



2nd. To translate from the system of the calculus into the 

 ordinary notation. 



Let r be the index of a, and q the sum of the indices of all the 

 other prime factors corresponding to perissad atoms, then 2r — q 

 is the number of H atoms. For the other elements, change the 

 symbols for prime factors into the corresponding atomic symbols, 

 retaining the index of each. 



Examples. 



Trichloracetic acid, a 2 ^ 3 *; 2 £ 2 . 



r =2, q=S, 2r-q = l, Formula H CI 3 C 2 2 . 



Iodide of phosphotetrethylium, u u cd(£>k 8 . 

 r=ll, q = 2, 2r-g = 20, Formula H 20 IPC 8 . 



Nitrate of ammonium, a 3 v 2 f 3 . 

 r = 3, q = 2, 2r-q = 4>, Formula H 4 N 2 3 . 



Oxychloride of phosphorus, « 2 $% 3 f . 



r = 2, 2 = 4, 2r-q = 0, Formula PC1 3 0. 



* Exceptional case, page 854. 



