178 SECTIONAL ADDRESSES. 



lengths of life of the treated animals, and the type and extent of disease 

 at post-mortem examination in treated and control animals has in every 

 case up to the present been similar. 



These compounds are interesting because the one delays death and 

 the other is entirely without action. They may afford a hint as to the 

 lines on which organic chemists should proceed, and perhaps show that 

 gold in the ionic form is desirable. 



The Internal Secretions. 



In the last twenty years much evidence has accumulated to show 

 that the glands of internal secretion are responsible for the regulation of 

 growth, of metabolism, and often for our appearance if not for our very 

 character. Exaggeration or diminution in the secretion of one or other 

 of the tissues may induce conditions so decided as to be obvious to 

 everybody, though the effects produced by minor alterations in the 

 co-ordination of the several secretions may not be so evident. Giants 

 and dwarfs, unusual pigmentation and anaemia, disproportion in the growth 

 of the skeleton, such as enlarged hands and face, bulging deer-like eyes 

 or oriental eyes and beards in women are noticeable to everyone ; exces- 

 sive fatness or emaciation, a choleric or bucolic temperament cause no 

 comment, yet may equally arise in the victim from a want of co-ordination 

 in the internal secretion. 



The general outlook and significance of drug therapy was led into 

 new channels when it was revealed that the animal body through these 

 glands elaborates its own drugs, stores them generally at the seat of 

 formation, and doles them out to the tissues to meet the needs of the 

 economy. Some of these drugs are of the nature of alkaloids comparable 

 with those elaborated by plants. It is a remarkable fact that when 

 Nature elaborates a drug in either a plant or an animal, that drug is 

 invariably the ideal drug for producing the action for which it is 

 characteristic. No drug relieves pain like morphine or produces local 

 anaesthesia so well as cocaine ; no drug paralyses the para-sympathetics 

 so perfectly as atropine or the motor nerves so effectively as curarine ; 

 strychnine supersedes all other drugs in exaggerating spinal reflexes, and 

 caffeine in its remarkable power of stimulating the psychical centres of 

 the brain. Of the animal drugs, adrenaline has a superlative effect on the 

 sympathetic system, pituitary on the uterus, and thyroxin on general 

 metabolism. 



The elaboration of the drugs in nature is on biological lines and the 

 key always fits the lock : it seems as if Nature always says the last word 

 on the particular type of drug she elaborates. Certainly organic chemists 

 have up to now done little to improve on her products. 



The Suprarenal Gland. 



The suprarenal gland is composed of two distinct organs. The medulla 

 elaborates an alkaloid named adrenaline, the action of which corresponds 

 with stimulation of the entire sympathetic system. What exactly its 

 functions may be in the animal economy is not certain ; its output under 



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