398 [Jan. 15, 



and distils unchanged. A determination of the density of its vapour 

 gave the number 5*241 : the above formula, corresponding to 2 vols. 

 of vapour*, requires the number 5'528. 



"When leucic ether is treated with solution of hydrate of baryta, it 

 gradually dissolves even in the cold; on heating the solution in a 

 water-bath, a liquid having the properties of alcohol distils off ; and 

 on separating the excess of baryta by carbonic acid and filtration, 

 the solution yields, on evaporation, a crystallizable baryta-salt which, 

 after drying at 100 C., gives on analysis numbers closely cor- 

 responding with the formula of leucate of baryta : 



Leucate of potash is similarly produced when leucic ether is 

 treated with an aqueous solution of caustic potash. It separates as 

 a semisolid soap upon the surface of the potash solution, if the latter 

 be concentrated. All the salts of this acid appear to be soluble in 

 water. 



Leucic acid in solution is obtained when dilute sulphuric acid is 

 added to leucate of baryta ; the acid has a sour taste, reddens litmus 

 strongly, and is readily soluble both in water and alcohol. It can 

 be boiled with water without decomposition, and traces only of the 

 acid distil off with the water. 



So far as I have studied its properties, leucic acid thus obtained 

 appears to be identical with that derived from leucin ; but it will be 

 necessary to establish this identity by a more rigorous comparison 

 of the two acids. 



The production of leucic acid from oxalic acid, as just described, 

 obviously affords an insight into the molecular constitution of the 

 class of organic acids of which lactic acid is the representative ; I 

 refrain, however, from offering any opinion upon a point which has 

 already given rise to so many hypotheses, until I have completed 

 the study of this reaction, and extended it to other homologous 

 bodies. 



* H 2 0=2 volumes. 



