CONSTITUTION OP CILYCOCOLL AND ITS DERIVATIVES. IQS 



CO.O CO.NH, 



CH.NH3 CFI.NH3 



I and I 



CH, CH. 



I ' 1 



CO.NHo CO.O 



but also of aspartic acids — 



CO.O CO.OH 



I I I 



CH.NPL Cli.XHg 



I and I 



CH., C^II, 



r ! . 



CO.OH CO.O , 



each of which is fnrtlier capable of existing as dextro-rotatory, laevo- 

 rotatory, and racemoid modifications. It must l)e frankly acknow- 

 ledged, liowever, that all the aspartic acids known at present appear to 

 possess one and the same (Constitution, the two active acids obtained 

 from the ordinary and the sweet asj)aragins being optical isomers, and 

 all the inactive aspartic acids (jl)tained in various ways being identical 

 among themselves and also with that produced on mixing the two 

 active acids in ei^ual quantities (Piatti : Bei:, 19, 1(!-S4 [ISNIÎ]; Engel: 

 Bull, 50, 150 [18S,S]). There are, however, certain points in the 

 chemistry of asparagin and aspartic* acid, which require further inves- 

 tigation. The singular fact that, of the two as])aragins which are 

 regarded to be opti(\al isomers, one is tasteless and the other exceed- 

 ingly sweet, the fact also that these two active asparagins, mixed in 

 equal quantities, do not produce an inacti\e racemoid com])Ound, are 

 some of the points above referred to. Moreover, the inactive aspara- 

 gin obtained from monoethyl a— aspartate (m. p. 105°) and which, 

 from its mode of formation, has to be represented by the formula. 



