628 EXPERIMENT STATION EECORD. [Vol. 35 



and tannins. In a greater length of time it may also be formed by the mixture 

 of lignin and proteins and also by the latter alone. A certain correlation is 

 observed between the artificial and the natural formation of humus, in that in 

 natural surroundings humification is restricted to those organic bodies which 

 readily undergo a similar transformation under the influence of very active 

 chemical agents. Humus can not be always identical in its chemical composi- 

 tion, but must contain the decomposition products of lignin, proteins, pigments, 

 tannic substances, etc." 



Humus acids in the light of the results of recent investigations, E. Guixy 

 (Internat. Mitt. BodenJc, 5 (1915), Nos. 3, pp. 232-2^7; If, pp. 3^7-368; abs. in 

 Ztschr. Angew. Chem., 28 (1915), No. 77, Refer atenteil, p. 487).— The author 

 reviews the work of others bearing on the subject and reports the results of 

 new experiments on the degree of acidity of different svibstances, including 

 dopplerite and beech leaves. 



A comparison of the acidity of the substances before and after extraction of 

 the bases showed evidences of the action of colloids. The results are taken to 

 indicate that all plants contribute to the acidity of humus. No direct relation 

 was found between the acid content of moor substances and the process of peat 

 formation. The acidity stood in inverse proportion to the plant food content. 

 The natural humus acids were found to form neither soluble alkali nor in- 

 soluble lime salts. It is thought that the previously formed humus acids in 

 living sphagnum are identical with the so-called humus acids. 



Report on experiments with bacterized peat or huniogen, F. J. Chittenden 

 (Jour. Roy. Hort. Sac, 4I (1915), No. 2, pp. S05-S26, figs. 2).— Five series of pot 

 and plat experiments are reported. The purpose was to determine the influence 

 of additions of bacterized peat on the growth of various flowers and vegetables. 



It was found that plant growth was greatly and uniformly increased by 

 bacterized peat in the indoor pot experiments, in which the material was used 

 at rates of 1 part of peat to 1, 3, and 7 parts of soil and the soil was watered 

 with a bacterized peat extract. Much less favorable results were obtained in 

 the outdoor plat experiments. In comparative lots 20 tons of barnyard manure 

 per acre gave better results than 1 ton of bacterized peat The full results were 

 obtained from the use of peat only when the supply of water was abundant. 

 " The results on the 'whole show that when prepared under the best conditions 

 bacterized peat is capable of acting as a very effective manure." 



The effects of radio-active ores and residues on plant life, M. H. F. Sutton 

 (Reading, Eng.: Sutton & Sons, 1915, Bui. 7, pp. 20, figs. 9). — This is a report 

 of a second series of experiments conducted during 1915, in which the results of 

 the 1914 experiments (E. S. R., 34, p. 821) are reviewed and the results obtained 

 with nine different radio-active materials when used on tomatoes, potatoes, 

 radishes, lettuce, onions, carrots, vegetable marrows, and spinach beets, and on 

 fruit, roots, foliage, and bulbs are reported. 



" The exi^eriments indicate no more hope of the successful employment of 

 radium as an aid to either horticulture or agriculture than did the trials carried 

 out in 1914." It is considered conclusive that the farmer and gardener need 

 look for no material benefit from radium, the chief result having been to em- 

 phasize the value of barnyard manure and complete artificial fertilizers. 



Experiments with green manures and green manuring on sandy and white 

 moss soils at Flahult, H. von Fellitzen (Svenska Mosskulturfor. Tidskr., 29 

 (1915), No. If-5, pp. 326-338, figs. 3). — Experiments on the reclamation of sandy 

 and white moss soils deficient in plant food, especially nitrogen, and having a 

 low moisture retaining capacity are reported. The rotation included rye, po- 

 tatoes, carrots, and different legimaes. 



