CHEMISTKY OF THE SUPKAKENAL GLANDS 79 



with alcohol and ether, then treated with H 2 O until the silver test for 

 chlorids became negative. The precipitate was suspended in alcohol and 

 precipitated with oxalic acid. The excess of oxalic acid was removed as 

 ammonium oxalate. The red brown filtrate was evaporated to dryness, dis j 

 solved in absolute alcohol an dallowed to evaporate in desiccators. He sus- 

 pected that his final product was a mixture of unchanged chromogen with 

 decomposition products of it. His analyses gave 40.83 per cent C, 9.1 per 

 cent H and 9.31 per cent N. This product contained Fe, but no S. Kru- 

 kenberg did not attempt to construct a formula, but from his figures 

 Moore calculated the empirical formula C 5 H 14 NO 4 . 



Krukenberg pointed out that the color reactions of the medulla were 

 similar in many respects to those of pyrocateehol. This was confirmed 

 by B runner, who also showed that these extracts reduced Fehling's solu- 

 tion. From this time, workers became convinced of the presence of a 

 pyrocateehol compound in these organs. 



Later Work. In 1894, Oliver and Schaefer(fr) reported that extracts 

 of the suprarenal glands, when injected intravenously into animals, caused 

 a marked, transitory rise in the systemic blood pressure. These reports 

 were followed by independent observations of Szymonowicz, and of Cy- 

 bulski. 



The striking effects on blood pressure and the successful clinical use 

 of suprarenal extracts as a local vasoconstrictor soon excited determined 

 efforts to isolate the compound which exerts this action and, as Brad- 

 ford says, the history of the attempts to isolate and synthesize this com- 

 pound forms one of the most striking and interesting chapters in the 

 history of biochemistry. 



Oliver and Schaefer(c) found that the pressor activity was confined 

 to the medulla and made some attempts to determine the nature of the 

 compound which produced it. They found that this compound was in- 

 soluble in absolute alcohol and ether, that alkalies injure or destroy it, 

 that it dialyzes and is not destroyed by gastric juice, and stated that this 

 compound is apparently identical with Vulpian's chromogen. However 

 the chemical work was delegated to Moore, who was then working in 

 Schaefer's laboratory. 



Miihlmann claimed that after treatment of suprarenal extracts with 

 HC1, a compound giving pyrocateehol reactions could be extracted by 

 ether, but he did not isolate it, He believed that pyrocateehol existed in 

 the medulla in a complex form. This work was not corroborated by that 

 of Giirber or by that of von Fiirth. 



Fraenkel extracted suprarenal glands with alcohol or water and, after 

 concentrating, extracted with boiling absolute alcohol. This extract was 

 then precipitated with acetone and finally with ether. He obtained a 

 syrupy residue which, on insufficient evidence, he regarded as pure. This 

 he called sphygmogenin and believed it to be a nitrogenous pyrocateehol 



