NOTES AND ABSTRACTS. 



595 



bulletin shows that many of the substances ordinarily added to the soil 

 as fertilizers have, in addition to their function as plant nutrients, " a 

 well-defined power to overcome and actually destroy toxic bodies." 

 Equal or greater improvement results from treatments that add nothing 

 to the soil in the nature of plant nutrients. The methods of work are 

 described, wheat being used for the experiments, and the following 

 compounds were experimented upon : — (1) Compounds arising from the 

 decomposition of proteid bodies ; aspartic acid (C 4 H 7 N0 4 ), asparagin 

 (C 4 H 4 N 2 0 3 ),glycocoll (C 2 H 5 N0 2 ), alanine (C 3 H 7 N0 2 ), tyrosin (C 9 H n N0 3 ), 

 and leucine (C G H 13 N0 2 ). Of these aspartic acid and tyrosin acted in the 

 most detrimental manner upon the plants. (2) Arising from decom- 

 position of lecithins : choline (C 5 H 15 N0 2 ), neurine (C 5 H 13 NO), were 

 both found to be toxic. (3) Other nitrogenous compounds : alloxan 

 (C 4 H 2 N.,0 4 ), guanine (C 5 H 5 N 5 0), xanthine (C 5 H 4 N 4 0.>), guanidine 

 (CH 5 N 3 ), skatol (CjHgN), pyridine (0 5 H 5 N), picoline (C 5 H 4 N.CH 3 ), 

 piperidine (C 5 H n N), quinoline (C 9 H 7 N), ricin, mucin, all except guanine 

 and xanthine, caused injury. (I) Non-nitrogeneous compounds : pyro- 

 catechin (C G H 4 (OH 2 ), arbutin (C 12 H l6 0 7 ), pyrogallol (C 6 H 3 (OH) 3 ), 

 phloroglucin (C G H 3 (OH) 3 ), vanillin (C 8 H 8 0^), vanillic acid (C 8 H 8 0 4 ), 

 quinic acid (C G H 7 (OH) 4 .COOH), quinone (C G H 4 0 2 ), cumarin (C 9 H G 0 2 ), 

 daphnetin (C 9 H (i 0 4 ), esculin (C l5 H 1G 0 9 ), heliotropine (C 8 H G 0 3 ), borneol 

 (C 10 H 18 O), camphor (C 10 H 1G O), turpentine oil (C 10 H, G ), were all more or 

 less toxic. 



Numerous interesting experiments are detailed showing how the toxic 

 conditions set up by these substances may be removed or ameliorated ; 

 boiling, the absorption of them by such a substance as carbon black, the 

 adding of a non-nutrient compound to the solution such, as pyrogallol, 

 the addition of various fertilizing materials such as nitrate of soda, were 

 all tried with a greater or less degree of success. — F. J. C. 



Soil Fertility, Some Factors influencing-. By Dr. 0. Schreiner 

 and H. S. Reed (U.S.A. Dep. Agr., Bur. of Soils, Bull. 40, June 1907; 

 3 plates). — The authors consider that it has been demonstrated that 

 many soils are unproductive, not because proper nutrients are lacking, but 

 because they contain substances actually deleterious to plant growth. A 

 considerable body of facts is cited in support of this conclusion. These 

 deleterious matters may be absorbed by various substances which may be 

 easily added to the soil, such as iron hydrate, carbon black, and so on. 

 In soil extracts of unproductive soils great development of plants has 

 followed the addition of such substances as two parts of pyrogallol per 

 million of extract, or ten parts of alpha naphthylamine per million of 

 extract. These two substances are without nutritive effect upon plants 

 and can only act by ridding the soil of the toxic substance. In some soil 

 extracts the toxic substance has been shown to be capable of passing- 

 over with the distillate when the extract is boiled. It is shown that 

 the roots of plants excrete substances which, in the case of wheat, are 

 more deleterious to the wheat-roots than are the excreta from other 

 plants ; while the excreta from oats are more harmful to wheat than 

 those from more distantly related plants, as Vigna and maize c Those 

 plants which succeed best in a rotation of crops with wheat produce 



