chemical character of the blood-pressure-raising constituent of the 

 gland. 



Whatever the probability may be of the correctness of this or that 

 view, it is to be noted that all of the above-named investigators have 

 based their conclusions on reactions made with aqueous, alcoholic or 

 acetonic extracts; none of them have even roughly isolated a definite 

 chemical compound. The subject is one of great difficulty, and our 

 own work is at present merely preliminary, but we have arrived at the 

 following conclusions which we believe to be borne out by our ex- 

 periments. 



First, we have found by isolating the blood-pressure-raising con- 

 stituent in the form of a benzoyl compound and decomposing it, that 

 the active principle is a substance with basic characteristics and that it 

 must in all probability be classed with the pyrrol compounds or with 

 the pyridine bases or alkaloids. 



Second, that pyrocatechin cannot be split off from the isolated ac- 

 tive compound by boiling with acids, as has been asserted. 



Third, we have found that a carmine-red pigment can be separated 

 from the sulphate of the active principle without destroying its 

 power to raise the blood pressure. 



Fourth, in addition to this, we have isolated from the crude benzoyl 

 product a volatile basic body which fumes in the air and which emits 

 an odor very much like that of coniine. 



Method of Isolating the Active Principle in the 

 Form of a Benzoyl Compound 



We have used sheep's glands in large quantity. The medullary sub- 

 stance of the fresh glands was scraped out, dried on the water-bath 

 at 60° C, ground up finely, and extracted with ether for several days 

 until the fats and the substance known as Manasse's jecorin were re- 

 moved. In this way a fine dry powder of a grayish white appearance 

 is obtained, the aqueous extract of which is very active in raising the 

 blood pressure. 



With 100 grammes or more of this powder, representing one kg. in 

 weight or about 1000 fresh glands, we proceeded as follows: The pow- 

 der is repeatedly extracted with warm ^vater acidulated with a few 

 drops of dilute sulphuric acid until the gland has yielded up all of 

 its chromogenic substances, as tested by Vulpian's reactions. This 

 aqueous extract is evaporated on the water-bath to a small bulk, a 

 large excess of strong alcohol is then added and the whole allowed to 

 stand 24 hours, by which time the proteids have all settled out. The 



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