RADIX ALTH^.E. 93 



taining from 3 to 30 fibres separated by parenchymatous tissue. Of 

 the cortical parenchyme many cells are loaded with starch gmnules, 

 others contain stellate groups of oxalate of calcium, and a considerable 

 number of somewhat larger cells are filled with mucilage. The last- 

 named on addition of alcohol is seen to consist of different layers. 



The woody part is made up of pitted or scalariform vessels, accom- 

 panied by a few ligneous cells and separated by a parenchymatous 

 tissue, agreeing with that of the bark. On addition of an alkali, 

 sections of the root a.ssume a bright yellow hue. 



Chemical Composition — The mucilage in the dry root amounts 

 to about 25 per cent, and the starch to as much more. The former 

 appears from the not very accordant analysis of Schmidt and of Mulder 

 to agree with the formula C^H^O^", thus differing from the mucilage 

 of gum arable by one molecule less of water. It likewise differs in 

 being precipitable by neutral acetate of lead. At the same time it 

 does not show the behaviour of cellulose, as it does not turn blue by 

 iodine when moistened with sulphuric acid, and it is not soluble in 

 ammoniacal solution of oxide of copper. 



The root also contains pectin and sugar (cane-sugar according to 

 Wittstock), and a trace of fatty oil. Tannin is found in very small 

 quantity in the outer bark alone. 



In 1826 Bacon, a pharmacien of Caen, obtained from althaea root 

 crystals of a substance at firet regarded as peculiar, but subsequently 

 identified with Asparagin, 0*H*N-0^ H-0. It had been previously 

 prepared (1805) by Vauquelin and Robiquet from Asparagus, and is now 

 known to be a widely-diff'used constituent of plants.^ Marshmallow 

 root does not yield more than 08 to 20 per cent. Asparagin crj-stal- 

 lizes in large prisms or octohedra of the rhombic system ; it is nearly 

 tasteless, and appears destitute of physiological action. Its relation to 

 succinic acid may be thus represented : — 



Succinic acid: CT^H* 1 nQQu 5 Asparagin: C-H3(NH-) -| p,^^TT . 



Asparagin is quite permanent whether in the solid state or dissolved, 

 but it is easily decomposed if the solution contains the albuminoid con- 

 stituents of the root, which act as a ferment. Leguminous seeds, 

 yeast or decayed cheese induce the same change, the final product of 

 which is succinate of ammonium, the asparagin taking the elements of 

 water and hydrogen set free by the fermentation, thus — 



C*H«N20' -I- H^'O -I- 2H =2NH^eH^0* 



Asparagin. Succinate of Ammonium. 



Under the influence of acids or bases, or even by the prolonged 

 boiling of its aqueous solution, asparagin is converted into Aspartate 

 of Ammonium, C^H^(NH'')NO*, of which the hydrated asparagin con- 

 tains the elements. 



These transformations, especially the former, are undergone by the 

 asparagin in the root, if the latter has been imperfectly dried, or has 



^ It plays an interesting part in the ger- the juice by means of the microscope and 



mination of the seeds of papilionaceous absolute alcohol, in which latter asparagin 



and other plants. It is abundant in the is insoluble. See Pfeffer in Pringsheim"s 



young plants, but in most it speedily dis- Jahrb. f. wigs. Bot. 1S72. 533 — 564. — 



appears. Its presence can be proved in 'QoxoifaD.'va. Bot. Zt'dung, 1878. SOlandseq. 



