2 INTERNAL SECRETION 



believed that the nervous system was the sole mediating agent 

 by which the consensus partium was maintained. 



Such was, naturally enough, the view adopted by clinicians 

 to explain disturbances of functional equilibrium. Derangement 

 of function in any direction was said to produce a change, both 

 qualitative and quantitative, in the nature of the stimuli and, 

 reacting through the nervous system upon other organs, was 

 believed to produce in them also a departure from the normal, 

 thus giving rise to the most varied pathological symptoms. From 

 this arose the doctrine of the reflex manifestation of diseases, a 

 doctrine which was until quite recently universally accepted and 

 is not, even now, entirely discredited. The changes, for example, 

 which for centuries have been known to take place in the organism 

 after suppression of the secretion of the sexual glands, whether 

 by castration or by the physiological phenomena of the climacteric, 

 were believed to result from a purely nervous reflex action. 



But, logically faultless though this hypothesis be, and 

 founded as it certainly is upon a sound physiological and anatomi- 

 cal basis, it has not always maintained an undivided supremacy. 

 Looking back over the fields of biology and general pathology 

 we find that the neural theory of the correlation of organs was 

 companioned by a belief in their humoral relationship, and that 

 this latter theory is even the older of the two. 



In the healing arts of primitive peoples, as well as in the 

 earlier periods of scientific medicine, remedies were employed 

 and measures resorted to, which are the direct forerunners of the 

 organo-therapy of to-day. Hahnemann's homoeopathy threw out 

 a branch isopathy which in certain directions proved itself 

 stronger than the parent stem. In every organic disease it was 

 the practice of isopathy to administer the healthy animal 

 organ ; fox-lung was given in pulmonary disease, wolf's liver in 

 liver troubles, ox-eyes in ocular affections, and so on. In spite 

 of the haziness of the ideas which prompted these measures, they 

 were certainly carried out in the spirit which animates the humoral 

 pathology of to-day, for they recognized the fact that each organ 

 plays a part in maintaining the balance of secretion and has 

 thus an influence upon the organism as a whole. 



The discovery of the circulation of the blood supplied a 

 second channel by means of which the different parts of the body 

 may be brought into relationship. And yet in the early days of 

 the new humoral pathology, at a time when changes in the con- 

 stitution of the blood-plasma were universally recognized as 

 causes of disease, the blood-stream was very rarely admitted as 

 a factor in the consensus partium. This was due to the fact that 

 at that time changes in the nature of the blood-plasma were 

 believed to result, partly from external conditions and partly from 

 retention in the blood of normal secretions. Thus, Bordeu (a 

 predecessor of Brown-Sequard, who lived in the second half of 



