80 GLANDS IN HEALTH AND DISEASE 



chemically pure state, of one of its hormones, 

 .adrenaline. This substance has not only been iso- 

 lated from the gland, but it has also been synthe- 

 sized in the laboratory. The organic chemist gives 

 to it the name orthodioxy phenyl-ethanol-methyla- 

 mine, and he knows that it is therefore related to 

 tyrosine, an important amino-acid obtained when 

 proteins are decomposed. 1 With the help of a little 

 fancy and a little fact, the physiological chemist 

 explains the indispensability of some of these 

 amino-aeids by declaring that they constitute the 

 raw materials for the manufacture of hormones. 



If we except the isolation of the hormone from 

 the thyroid, the isolation of adrenaline remains the 

 only case on record of the extraction of a hormone 

 in a pure condition from its gland. "It is one of 

 the greatest triumphs of physiological chemistry," 

 writes Vincent, "that within seven years of the dis- 

 covery of the powerful effects of extracts of the 

 adrenal medulla by Oliver and Schafer (Schafer's 

 discovery was made in 1894), the active principle 

 was obtained in crystalline form, and that five 

 years later its composition has been so completely 

 ascertained that it has been synthesized, and the 

 pure active synthetic products can be obtained 

 from the manufacturing chemists." 



The men primarily responsible for the isolation 



'See the chapter on Ammo- Acids in the author's book on 

 Vitamines. 



