336 JOURNAL OF THE WASHINGTON ACADEMY OF SCIENCES VOL. 11, NO. 14 



fact that it is retained in the system a long time and but slowly de- 

 composed. In a very similar manner it is possible to make an element's 

 action milder, more continuous and free from local irritant action. 

 Iodoform is a case in point. Its action is that of iodine; but iodine 

 itself is too powerful for local application to wound surfaces. Iodo- 

 form is slowly decomposed on wound surfaces subjecting them to the 

 mild continuous action of iodine so that there is little local irritation. 



Except for salvarsan, the cases just given are examples in which the 

 modification of the action of the drug was in the main designed to 

 accomplish a modification of the intensity and site of action of a 

 well-known drug substance rather than to modify its specific action or 

 to create a new drug with a modified specific or even a totally new 

 physiological action. The investigations and the line of reasoning 

 which lead up to the production of the valuable local anesthetic, 

 novocaine, are perhaps typical of the latter form of chemo-therapeutic 

 research. The object of these investigations was to develop a drug 

 with the local anaesthetic action of cocaine but devoid of its objection- 

 able toxic effects. Ecgonine, the mother substance, of cocaine, has the 

 following formula: 



CH (COOH) 



CH (OH) 



Kinhorn^^ discovered that if he esterified the carboxyl (COOH) 

 group of ecgonine with a methyl (CH3) group and the hydroxyl (OH) 

 group with a benzoyl group (CO.CeHr,) he obtained the very anaesthetic 

 natural base cocaine : 



c coo CHs 



CH O CO CeH. 



This led him to make a large number of benzoyl esters, many of which 



^'A. EiNHORN. Ueber neue Arzneimittel, Ann. d. Chemie 371: 125. 1909. 



