THE SUPRARENAL CAPSULE 583 



resembling those seen after removal of the glands. The question 

 thus arises whether the animals die from the loss of a specific 

 secretion or from the accumulation of a toxic substance which 

 would normally be removed by the gland. The toxic effects of 

 the blood do not appear to be due to auto -intoxication with the 

 substances which are found in the normal gland, for the urine and 

 tissues of animals deprived of their capsules were examined by 

 Moore and Purinton for the suprarenal chromogen, and were tested 

 physiologically for the presence of the active substance with 

 negative results. Other observers have demonstrated the origin 

 of the active substance in the living gland ; the blood collected 

 from the adrenal vein gives a reaction similar to that of the 

 glandular substance itself, while blood from other vessels does not 

 possess this property. Oliver and Schafer found that extracts made 

 from the diseased glands of patients who had died from Addison's 

 disease did not possess the active principle of the healthy gland. 



The first important work upon the physiological effects pro- 

 duced by extracts of the suprarenal capsules is due to Oliver and 

 Schafer, who showed that extracts of the gland prepared with 

 water, alcohol, or glycerine contained a specific substance which 

 produced a marked contraction of the arterioles ; a rise of blood 

 pressure is thereby rapidly produced, and may mount up to two 

 or even five times the normal height ; the rise lasts about two 

 or three minutes. The action is a peripheral one, the contraction 

 of the arterioles occurs equally well after section of the spinal 

 cord, and after division of the nerves which supply the limb. The 

 active principle is contained only in the medulla of the gland, and 

 it is not destroyed by boiling or gastric digestion. The injection 

 of large doses produced death in the case of rabbits, but in 

 dogs and cats only a slight transitory disturbance was seen. 

 Schafer showed that the extract of the gland was a most powerful 

 styptic, which could be safely used to check haemorrhage from small 

 blood-vessels in man. 



Various attempts were made by Abel and von Fiirth to isolate 

 the active principle of the gland, but this was first accomplished 

 by Takamine, who named the substance adrenalin. It is a white, 

 light, crystalline substance, with a slightly bitter taste, sparingly 

 soluble in water and perfectly stable in a dry form. In alkaline 

 and neutral solutions adrenalin is a powerful reducing agent and 

 absorbs oyxgen from the air. All aqueous solutions on standing 



