traced by the formation of a benzoyl product, its reducing power and 

 its color reaction with ferric chloride are all points which can be urged 

 in support of this view. Furthermore, cupric acetate, the serviceable- 

 ness of which as a precipitant of carbo-pyridine bases has been shown 

 by Gautier and Landi,* also precipitates our active principle; and 

 iodine chloride, which Dittmarf found to give brown or yellow halo- 

 gen addition-derivatives with a large number of the alkaloids, gives 

 with a neutral or slightly acid solution of our active sulphate a brown- 

 ish flocculent precipitate. 



Of less weight in this connection, but nevertheless of some value, 

 is the fact that its physiological action and its power in small doses is 

 again in accord with what is known of alkaloids. Strychnine, thebaine 

 and other alkaloids are readily called to mind as able to raise the 

 blood pressure, and recently Tunnicliffe;{: has placed piperidine in the 

 same list. The pyrrol§ bases are also physiologically active, although 

 less attention has been paid to them. 



Pyrocatechin cannot be split off from the 

 Blood-Pressure-Raising Constituent 



As already said, Muhlmann has stated with great positiveness that 

 the blood-pressure-raising constituent is pyrocatechin joined to some 

 other substance, probably an acid. Muhlmann does not offer sufficient 

 proof for his conclusion; and even had he proved the presence of 

 pyrocatechin in the gland itself, this is a very different thing from 

 showing that it enters into the chemical constitution of the blood- 

 pressure-raising constituent. 



We have repeated Miihlmann's work and have found that after 

 boiling the medullary substance with hydrochloric acid, the ether 

 takes up a trace of Vulpian's substance, as well as a substance that re- 

 duces Fehling's solution. 



The ether residue also gives a precipitate with neutral lead acetate 

 which, on decomposition with dilute sulphuric acid, sets free a com- 

 pound that gives with ferric chloride the reaction so characteristic 

 of pyrocatechin. Our blood-pressure-raising constituent is not pre- 

 cipitated by lead acetate and could not, therefore, have been responsi- 

 ble for this result. 



*Compt. rend., cxiv (1892), 1154-1159. 

 f Berichte d. deutsch. chem. Gesellsch., xviii, 1612. 

 + Centralbl. f. Physiol., x, No. 25, 777. 



§ Jac. Ginzberg, Ueber das Verhalten des Pyrrols, etc., Inaug. Diss., Konigs- 

 berg. 1890. 



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