Furthermore, on decomposing a fairly large quantity of the crude 

 benzoyl product before referred to and shaking out the resulting 

 benzoic acid with ether, we have twice found that the ether has taken 

 up in addition to the benzoic acid a small quantity of a substance 

 which reduces Fehling's solution and gives a precipitate with neutral 

 lead acetate. On decomposing the resulting lead compound with 

 dilute sulphuric acid and neutralizing the filtrate, we obtained a 

 solution which behaved with ferric chloride in the way characteristic 

 of pyrocatechin. The quantity of this lead compound obtained has 

 been too small for analytical purposes. 



We consider it, therefore, still imcertain whether or not a little 

 pyrocatechin is present in the gland. 



That the blood-pressure-raising constituent is, however, not a pyro- 

 catechin derivative seems to us certain. To prove this we used, not the 

 entire gland nor the medullary substance, but the active principle 

 itself, as isolated by us by decomposing the benzoyl compound. 



We have used large quantities of material representing in each 

 experiment the active principle of several thousand glands. We have 

 boiled this with hydrochloric acid of varying strength and for varying 

 lengths of time, and in no case have we been able to find in the ether 

 used as a solvent any trace of a substance that would reduce Fehling's 

 solution or give a precipitate with lead acetate. Inasmuch as some of 

 the chromogenic substance always passes into the ether from acid 

 solutions, these two reactions are both necessary to establish the pres- 

 ence of pyrocatechin. In other words, we have failed to split off pyro- 

 catechin from the active principle as isolated by us. If present, it 

 could hardly have eluded our search, for even a minute quantity may 

 be made to give a precipitate with neutral lead acetate. 



We propose during the coming autumn to continue this work. Hav- 

 ing made arrangements for the use of a large amount of material, we 

 hope to secure both the benzoate and the sulphate in a form pure 

 enough for analysis and for further chemical study. 



Summary 



We may summarize the results of our work as follows: 

 The blood-pressure-raising constituent of the suprarenal capsule 

 may be completely precipitated from an aqueous extract by treat- 

 ment with benzoyl chloride and sodium hydrate, according to the 

 Schotten-Baumann method. 



On decomposing the resulting benzoyl products, a residue is ob- 

 tained which possesses great physiological activity. It gives the color 



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