1010 EXPERIMENT STATION RE(X)RD. 



licini;- placed in water eultures of nonual solutions was 52 days for 

 fonnic. 2S davs for acetic, and i~ days for |)ro])ioiiic acid. The inju- 

 rious iiiHucnce of these acids upon the ])lants\\as mostly shown by the 

 effect upon the roots. The proto})lasni of the cells of the roots becomes 

 oranular, while the younoer cells ai'c killed outrioht. It wa.s thouglit 

 possible to accustom plants to acids by bejiiiuiini;- with dilute solutions 

 and increasing the concentration, so that plants may not be injured l)y 

 full normal s(reni>ths. It Avas found that the plants and \ esscls reipiire 

 frequent cleansino- of fungi and bactei-ia, as these solutions are good 

 nutrient media for cryptogamic plant growth. A concentration of 

 solutions that Avill prevent the functions of the cotyledons and thereby 

 reduce the plant to a state of starvation was necessary as preliminary 

 to the nutrition of })iants. Pea seedlings were kept for 80 days or 

 more in a normal foi'uiic-acid solution. The plants grevv' and develoi)ed 

 normally, although somewhat reduced in size. 



The author Ixdieves that his experiments show the fallacy of the 

 claim tliat phos})hates. sulpliates. and alkalies are necessary for plant 

 nutrition. 



The toxic action of acids and their sodiuni salts on lupines, 

 K. II. Tkuk (AiJtrr. Joar. Sci^Jf. sc:. f) {1900)^ .Va. ol.pp. lS.i-192).— 

 In previous papers dealing with the toxic action of dissolved salts and 

 their electrolytic dissociation, evidence Avas presented on the ionization 

 of the molecule on the poisonous properties exerted by these sul)- 

 stances on the radicles of Lupin i/.s alh>/-'<. The toxicity of the acids 

 was found to be largely due to the action of hydrogen ions formed in 

 the aqueous solution. 



In the present paper the effect of certain series (^f acids and their 

 salts on the lupine is given, from which it appears that in the inorganic 

 acids there is very free ionization. " Practically com})lete dissociation 

 exists at their death limits for lupines. The sodium salts of these 

 acids, as far as tested, agree in having a low toxic \!due. As a ride, 

 the organic comi)ounds offer somewhat greater difficulties, the ioniza- 

 tion of the molecule being seldom conq)lete at tlu' death limit. 



The fatty -acid series was examined, from which it was found that 

 formic acid was distinctlv the most toxic member of the group. The 

 sodium salts sIiowcmI little difference in their action, the formate, pro- 

 pionate, and ))utyrate giving identical death limits. The acetate was 

 found to l)e \ery weak in its poisonous action. 



The aromatic series was investigated, and in general these acids 

 showed a considerable variation in tlieii' toxic values due to their 

 chemical structure. In general, the anions of organic acids were 

 found to possess relatively slight toxic properties, sometimes so slight 

 as to be neglected, as in the case of acetic and hippuric acids. The 

 sodium ions are but weakly toxic and the anions sometimes relativel}^ 

 ineffective. 



