166 THERAPEUTICS AND PHARMACOLOGY 



The most surprising feature in the action of substances of the 

 organs is presented by the constituent of 'the supra- renal capsule, 

 adrenalin, not an albuminoid body, it is true. In order to better 

 illustrate the importance of the new domain, the following phar- 

 macodynamic experiment may be mentioned. Doses of cocain 

 which are absolutely fatal to animals are easily borne in the pre- 

 sence of adrenalin without any injurious effect whatsoever. These 

 substances, as they are found in the body of animals, are certainly 

 of importance for the life-processes themselves. Taken from the 

 animal body, they have the same effect as the human product, 

 and can thus be employed as curative agents in man. 



But medical chemistry had already undertaken researches which 

 were not indeed utilized therapeutically at once, but came to exert 

 great influence on therapeutics. In 1869, Zuelzer and Sonnenschein 

 proved that alkaloidal bodies may be formed by the decomposi- 

 tion of the organic substances of the organism, and later on the 

 theory of toxins was derived from this observation. This again 

 has led to von Behring's remarkable and far-reaching theory of the 

 anti-bodies formed in the organism. 



How to make the substances obtained from the bodies of ani- 

 mals useful for therapeutics, depends upon the state of our physi- 

 ological and chemical knowledge, and especially on the train of 

 ideas arising in connection with these subjects. This can be seen, 

 for example, in the case of the esters of cholesterin, the composi- 

 tion of which was already discovered by Berthelot, but not in con- 

 nection with biological investigations. On the other hand, choles- 

 terin esters had been observed in the form of wool-fat, and the 

 impure product was used medically and cosmetically even in an- 

 cient times for its curative powers. It was proved that a functional 

 significance as regards the animal organism must be attributed 

 to cholesterin esters, for they are present in mammals, birds, and 

 all creatures whose external surface is of keratinous character. 

 They give luster to the skin, but act chiefly, so to say, as a protective 

 varnish. The white substance of new-born children is therefore very 

 properly termed cheesy varnish (vernix caseosa). It was formerly 

 thought to consist of glycerine fat, but it is actually composed of 

 cholesterin esters. The higher members of these esters are charac- 

 terized by the physiological properties of wax. Gottstein has shown 

 that this substance offers no food for microbes, is very stable, dif- 

 ficult to saponify, and not decomposed by the oxygen of the air' 

 as are other fats. Thus it forms a protective matter, especially 

 effective by reason of its waxy nature, and this has led to the pro- 

 duction and application of therapeutic substances similar to choles- 

 terin ester, as, for example, fetron. 



The influence of pathological anatomy on therapeutics belongs 



