1 78 INTERNAL SECRETION 



that, when alcohol or acetate of lead are added to suprarenal ex- 

 tract, the by-substances are released, and the addition of concen- 

 trated ammonia results in the precipitation of adrenalin in the form 

 of microscopic crystals. These are further purified by repeated 

 solution in acids and precipitation by means of ammonia, until 

 eventually, clusters of crystals composed of prismatic needles and 

 rhomboid scales are formed. These adrenalin crystals dissolve 

 slowly in cold water and somewhat more readily in hot. They 

 dissolve freely in diluted acids, and form salts ; their reaction upon 

 litmus paper is weakly alkaline. They are not readily soluble 

 in alcohol, and they are insoluble in chloroform, amylic 

 alcohol, carbon bisulphide, ether, acetone, and benzine. In 

 accordance with its phenol nature, adrenalin is soluble in the 

 caustic alkalis, but not in the alkali carbonates and ammonia. It 

 cannot be precipitated by means of potassium mercuric iodide, 

 picric acid, tannic acid, phosphoromolybdanic acid, phosphoro- 

 wolframic acid, or mercuric chloride ; but ' it is reducible by 

 Fehling's solution and by ammoniated solution of silver. When 

 exposed to the air, the watery solution colours red and after- 

 wards turns brown ; the addition of ferric chloride produces the 

 characteristic green coloration.* 



Numerous experiments were undertaken by Aldrich, Bertrand, 

 Abderhalden and Berger, Jowett, Friedmann, v. Fiirth, Pauly, 

 Stolz, with the object of analysing the elements and ascertaining 

 the weight of the molecules, and these revealed the more intimate 

 characterization of adrenalin (epinephrin, according to Abel, 

 suprarenin, according to v. Fiirth). This substance is empirically 

 formulated as C 9 H 13 NO 3 . The following formula expresses its 

 constitution : 



OH 



CHoNH.CH, 



Adrenalin contains a benzol nucleus which is substituted in 

 the 2, 5, 6- position. Three hydroxyl groups (OH) are present in 

 the adrenalin molecule and, of these, two are placed in the vicinity 

 of the benzol nucleus in the 5, 6- position. The molecule contains 

 a methylimid group. 



Stolz succeeded in obtaining a substance, by a synthetic 

 process, which possesses pharmacological properties exactly 

 similar to those of adrenalin. 



If chloracetopyrocatechin which is obtained from the action 

 of chloracetylchloride upon pyrocatechin is treated with ammonia 



* The preparation known as "Adrenalin Takamine " (put upon the 

 market by Parke, Davis and Co.) is adrenalin in combination with hydro- 

 chloric acid, in a solution (i : 1000) of sodium chloride and chloreton, the 

 latter being a derivative of chloroform and aceton. 



