CHAPTER XV. 



ORGANIC ACIDS AND SALTS. 



Consult 



Fresenius. Qual. Anal. ' Organic acids.' 

 Read 

 De Vries. Bot. Zeit. 1879. 

 Kohl. Bot. Cent, xxxvm. 1889. 

 Wehmer. Bot. Zeit. 1889. 

 Id. 1891. 



Landw. Vers.-Stat. XL. (1892). 

 Doebner. Ber. d. d. Chem. Gas. (xxvii.) 1894. 



Organic acids. 



It is doubtful whether any of these compounds are 

 plastic, and it is almost certain that the lower members of 

 the series such as acetic, malic, oxalic, etc. are not, but 

 many of them are certainly indirectly useful in meta- 

 bolism. 



It is not generally necessary to ascertain exactly to 

 what acids the acidity in any case is due, but it may be 

 required to compare the amounts of acid present in tissues, 



