GENERAL SYNTHETIC METHODS. 



The amine is readily convertible into the hydrate, and the hy- 

 drate into the chloride, bromide, or iodide ; which last bodies, or 

 their metal derivatives such, for example, as sodium-ethylate 

 C 2 H 5 .NaO, and sodium-ethyl C 2 H 5 .Na are the forms of alcohol 

 most usually employed in actual synthetic processes. 



(87.) Prior, then, to this discovery by Wurtz and Mendius, of 

 means for passing from the acid to its alcohol by hydrogenation, 

 although many important syntheses had been effected, there had 

 been no consecutive series of syntheses. The previously known 

 processes would allow us to pass from certain mobile members 01 

 one group to certain immobile members of the next, but would 

 carry us no further. Nowadays, however, by transforming the 

 immobile acid into the mobile alcohol, we can proceed continu- 

 ously through an apparently unlimited series of synthetic opera- 

 tions. Thus, letting CO stand for the transferable part of carbonic 

 anhydride CO 2 , phosgene-gas COC1 2 , and aqueous prussic acid 

 CHN.H 2 0, we have the following series of operations leading to 

 the production of fatty acids and alcohols of any degree of com- 

 plexity, each of them capable of metamorphosis into scores of 

 allied compounds; which, again, are capable of entering into com- 

 bination with one another, as explained in my second lecture, to 

 form still more numerous and complicated polymerone bodies. 



Methylic 

 ( i -Carb. alcohol C H 4 



Acetic 

 U-Carbonacid CHO a 



/"2-Carb. alcohol 

 \3-Carbon acid 



/ 3 -Carb. alcohol 

 (,4-Carbon acid 



Ethylic 

 C a H 6 

 Propionic 



Propylic 

 C 3 H 8 



Butyric 



C 4 H 8 0, 



CO = 



H 4 = 



CO = 



Acetic 

 C a H 4 0, 



Propionic 



Ethylic 

 C a H 6 



Propylic 

 C 3 H 8 



Butyric 



CO 



;. &c. 



