4 INTERNAL SECRETION 



Bernard showed that, in the case of the liver, in addition to 

 the external secretion of gall there is an internal secretion or 

 glycogenesis, that is to say, the aggregation of glycogen and the 

 formation of sugar, the latter being afterwards conveyed into the 

 blood-stream. He endeavoured to prove that the function of 

 internal secretion is under the control of the nervous system. 



That the composition of the blood is susceptible to the 

 influence of the specific products of individual organs was, as we 

 see, known as long ago as the middle of the last century. Even 

 the designation " internal secretion " dates from that time. And 

 yet the introduction of the theory of the internal secretions is 

 universally ascribed to Brown-Sequard. This is because he was 

 the first to express the idea* that all glands, with or without ducts,^ 

 supply to the blood substances which are either useful or essential, < 

 and the lack of which may produce pathological signs. It was 

 not until twenty years later that he was able to give experimental 

 proof of his views. 



The actual date upon which the doctrine of the internal 

 secretions may be said to have been born is June i, 1889. It was 

 the occasion of that memorable meeting of the Societe de Biologie, 

 Paris, when Brown-Sequard, then 72 years of age, described the 

 experiments which, in order to prove his hypothesis, he had 

 carried out upon his own person, by the subcutaneous injection 

 of testicular extract. He found that after the injections, and 

 indisputably as a result of them, he experienced an access of 

 physical strength and an invigoration of cerebral function which 

 were quite extraordinary. Appetite improved, the bowels were 

 regulated, and there was a marked increase in mental activity. 

 This lecture and the detailed publication which followed it, a few 

 weeks later, were not only the actual foundations of the theory 

 of internal secretion, but they furnished the first practical appli- 

 cation of a new method of treatment, namely, that now known 

 as organo-therapy, or the Brown-Sequard method. 



It is not possible to estimate Brown-Sequard's work at its 

 proper value, unless it is kept distinct from the method which he 

 inaugurated and more especially from the abuses which followed 

 it, with which Brown-Sequard himself was unfortunately not 

 entirely unconnected. What he really did do was to prove 

 by experimental means the existence of a process of internal 

 secretion, which is in the nature of a chemical interchange between 

 the different organs and which is of the highest importance to 

 the economy. His theories were at once accepted in France and 

 to some extent in England. German physiologists and clinicians 

 were extremely sceptical. Nevertheless it should not be forgotten 

 that Hansemann, in Germany, soon afterwards adopted a similar 

 standpoint. Like Brown-Sequard, he assumed a physiological 



* In his address before the Medical Faculty of Paris in 1869. 



