824 BOTANY AND PHARMACOGNOSY. 



The gold salt of aconitine is amorphous when first precipitated 

 but may be obtained in three crystalline modifications by the 

 use of various solvents.* 



Aconitine. Crystals from alcoholic solutions (Fig. 142). 



Orthorhombic : a: b: c = 0.5456 ; i : 0.3885.! 



Forms observed: Brachypinacoid (010); macropinacoid 

 (100); and pyramid (121). 



Angles: The angle between the edges of the pyramid (121) 

 on the brachypinacoid (010-121 A010-I21) = 70 54' (normals); 

 angle between the edges of the same pyramid on the macro- 

 pinacoid (100-121 A ioo-i2i)=:75 40'. 



Cleavage parallel to the macropinacoid. 



Habit : Commonly tabular on the brachypinacoid ; the crystal 

 more or less elongated on the c axis and bounded by the macro- 

 pinacoid and the pyramid (121); sometimes tabular on the 

 macropinacoid. In the former case the angle of the termination 

 is 109 06' and in the latter 104 20'. 



Optical properties: 9 = c; Jl = 6; t^^a. The axial plane 

 is the brachypinacoid. Bxa^= a; optical sign H-. 2E^^=^^6 10'. 

 Dispersion of the axis strong ^ p <^y. When the crystal is of the 

 second habit mentioned, i.e., tabular on the macropinacoid. an 

 interference figure is observed. Owing to the strong dispersion 

 of the axes the hyperbolae are colored. 



ASPARAGIN (C^H.N.Og + H.O). 



Asparagin (y8-asparagin, the monamide of aspartic acid) 

 is an amido compound which is most widely distributed 

 throughout the vegetable kingdom. It is not only found in 

 reserve organs as the tubers of the potato and dahlia, the roots 

 of althaea, belladonna, etc. , and the seeds of the chestnut tree , 

 but it also occurs in young shoots as of asparagus and in peas, 

 beans, and other members of the Leguminosas. Asparagin has also 

 been detected in some of the fungi as the Agaricineae and certain 

 of the Myxomycetes. Unlike certain derivatives of urea it is a 



*J. W. Rriihl, Die Pflanzen-Alkaloide. 



fA. E. Tutton, Zeitschr. f. Krystallog., i8gi, 19, p. 178. 



