144 BASIC BODIES. 



almost simultaneously by Laurent and Gerhardt,* by Cahours,f 

 and by Horsford, indicate that in leucine there is contained 1 equi- 

 valent of hydrogen more than Mulder had assumed, and continues 

 to assume, in his most recent investigations.J Hence leucine, 

 which, moreover, crystallises without water of crystallisation, 

 contains : 



Carbon 12 atoms .... 54'96 



Hydrogen 13 .... 9'92 



Nitrogen 1 .... 10'68 



Oxygen 4 .... 24'44 



100-00 



Its atomic weight =163 7 "5. 



Since leucine possesses scarcely any basic properties, the view 

 that it is a conjugated ammonia=H 3 N.C 12 H 10 O 4 5 is the least pro- 

 bable hypothesis regarding its theoretical composition. From 

 Liebig's experiment, to which we have already alluded, that 

 leucine with hydrated potash yields valerianic acid besides volatile 

 products, no theoretical formula for this body can be provisionally 

 deduced ; but Gerhardt and Laurent, as well as Cahours, have in 

 part proved it to belong to the series of homologous bodies with 

 the formula C n H n+1 NO 4 , to which, as we shall presently see, 

 sarcosine and glycine pertain. But Cahours, || and subsequently 

 Strecker,^[ availed themselves of Piria's mode of proceeding, by 

 which he decomposed the amide-compounds by nitric oxide (see 

 p. 36) into water, nitrogen, and the original acid, in order to 

 obtain the above-mentioned leucic acid from leucine. According to 

 this view, leucine should be regarded as the amide of this acid: since 

 H 4 NO.C 12 H U O 5 2HO = C 12 H 13 NO 4 , the theoretical formula for 

 this substance must be = H 2 N.C 12 H n O 4 . 



Combinations. According to Gerhardt and Laurent, leucine, in 

 combination with acids, yields very beautifully crystallisable salts, 

 but they bear much more the character of conjugated acids, so that 

 we might regard leucine in itself as an adjunct ; against which view, 

 however, it may be observed that here the adjunct loses no water, 

 as in other cases it usually does on entering into combination, and 

 on separation takes up no water; these combinations are, however, 



* Corapt. rend. T. 27, pp. 256-258. 



t Ibid. pp. 265-278. 



J Scheikund. Onderzoek. D. 5, pp. 371-377. 



Ann. d. Ch. u. Pharm. Bd. 57, S. 128. 



II Compt rend. T. 27, pp. 265-268. 



f Ann. d. Ch. u. Pharm Bd. 68, S. 52-55. 



