THE MODERN THEORY OF CHEMICAL TYPES. 1G7 



The following are examples of the di;plicatiou and triplication of the hydro- 

 gen and ammonium types : 



Tvpe. Cliloro-sulphuric acid. Chloride of succinvle. 



H2 I S2 O4" ( Cs H4 O4" \ 



Hz] CI2 I CI2 f 



Type. Siiccinimide. 



H. ) ■ Cb H4 O4" ) 



H2) H2 ) 



Type. Oxychloride of phosphorus. 



H3 ) P 0,"' I 



H3} C13 J ' 



Type. Citramide. 



H3 ) C12 H5 Og'" ) 



H3 } M H3 > X3. 



H3 ) H3 ) 



These derived types are connected with the primary types by the hypothesis 

 that a "polyatomic" radical may replace several atoms of hydrogen in the 

 primary type. Thus — 



Anhydrous sulphuric acid. Anhydrous succinic acid. 



S2 04"|02. C8H4 04"j02. 



Sulphurous acid. 

 S2 O4" I 

 Succinimide. 



The following examples illustrate the use of the type method of expressing 

 a chemical reaction — e. g., that of hydrochloric acid with hydrated oxide of 

 ammonium. 



By the former method it would be — 



N H4 + H CI = N H4 CI + H O 



By the type method — 



H 

 NH 



j0^+*^}=N\}+g|0. 



Again : by the action of oxychloride of phosphorus upon acetate of soda, 

 chloride of acetyle is formed together with phosphate of soda, which reaction 

 is represented. 



By the former method — 



P O2 CI3 + 3 (N, 0, C4 H3 O3) = 3 N^O, P O5 + 3 (C4 H3 O2) CI. 



By the type method — 



P O2'" ) ^ . /C4 H3 O2 ) ^ \ P O/" ) o + -W ^^ ^^ ^2 

 CI3 } + M Na ] ^') - Xa3 r^« + M CI. 



Some regard the type method of imagining a body as essential in the nature 

 of matter ; to these the type of the same body is invariable, with which, if 



