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Chemistry. — "The (iinldi's o/' <i and ii-tfni/t/oproitionic ncid.'". By 

 Prof. A. P. N. Fkanciiimont and Dr. H. Friedmann. 



(Communicaled in the meeting of October !28, 1905). 



Some lime Jigo, I was asked for information as to a snbstance 

 isolated in J 873 by Uai'mstahk fmm some nrines. lie describes it 

 as wliite prisms some millimetres lon.ii' and reseniblini»' iiippni-ie acid 

 not only in form bnt also in bistre. It is fairly readily sobible in 

 boiling- water, with diftienlty in cold w^ater and spirit of wine, in- 

 soluble in absolute alcohol and ether, and sutlers no decomposition 

 when heated to 250°. It is a neutral substance Avliich, however, 

 yields with acids, hygroscopic compounds ditïicult to crystallise, and 

 gives a precipitate with mercuric nitrate. The analysis led to the 

 formula (■., H^ O N,. By means of nitrous acid he obtained from it 

 a li(piid acid and from this he prepared a zinc salt, which in zinc 

 and Avater content corresponds with the zinc salt of sarcolactic acid. 

 This zinc salt Avas very soluble in water and in spirit of wine, and 

 from this he concluded that it really consisted of zinc sarcolactate. 

 He also showed that under the intlnence of alkalis, one nitrogen 

 atom is readily converted into ammonia and the other into ethylamine, 

 carbon tlioxide being also formed. 



From this he concluded that his substance was the amide of 

 «-aminopropionic acid oi", as he called it, the diamide of lactic acid. 



Beilstein in his text-book, mentions Baumstakk's substance as the 

 amide of rf-aminopropionic acid but adds a point of interrogation, 

 and rightly so. for Baumstark has tried to control the conclusion 

 drawn from his analytical research l)y synthetically preparing the 

 diamides of the lactic acids, or amides of the amino-propionic acids, 

 and comparing them with his substance from the urine; from those 

 experiments he drew the opposite conclusion, and declared the previous 

 idea to be incorrect. 



But if we look at the synthetical metiiods apjilied by Baumstark, 

 it is at once evident that he could obtain nothing else but mixtures, 

 which he has not separated but seems to have regarded as pure 

 substances whose properties were totally dilferent from that of his 

 substance from nrine. 



Moreover, many, particidarly physical jn-operties such as melting 

 point, solubility, neutrality etc. of the substance from urine, are not 

 those wdiich we might reasonably expect of the amides of the amino- 

 propionic acids. 



None of the amides of the aminopropionic acids beii;g kinnvn, I 



33 



Proceedings) Koyal Acad. Amsterdam. Vol. Vlil. 



