822 EXPERIMENT STATION RECORD. 



"(3) The form of humic acid obtained from eaue sugar, wliicli retsembles 

 most closely the natural acid, differs greatly in chemical structure from the 

 latter. 



"(4) The artificial acid is unaltered in composition by conversion into the 

 ammonium salt and reprecipitation. 



"(5) Humic and saccharo-humic acid and their potassium salts are utiliz- 

 able by Penicillium as sources of organic carbon. 



"(6) Potassium hnmate and, to a less extent, potassium saccharo-humate 

 serve as organic nitrogen food compounds for Penicillium. 



"(7) The conclusions drawn from the physiological results of experimental 

 cultures of Penicillium in the acids and their potassium salts are in concord- 

 ance with those arrived at as the result of chemical analysis of the compounds." 



The presence of secondary decomposition products of proteids in soils, O. 

 ScHREiXEU and E. C. Shorey {Jour. Biol. Chem.. 3 (1907), Xo. 3. i>i>. 

 XXXVni, XXXIX; ahs. in Chem. AM., 1 {lUOl), Xo. 11, p. 2259).— The prepa- 

 ration of picoline carboxylic acid from sodium hydroxid extract of soils is 

 described. See also a previous note (E. S. R., 19, p. 419>. 



The importance of micro-organisms ia the circulation of nitrogen in nature, 

 C. Bakthel (K. Landtbr. Alcad. Huiidl. och Tid.skr., ',n {1901), Xo. 4-5, pp. 

 32 '1-334, fiff- O- — -^ discussion of I'eceut investigations on this subject. 



Progress in legume inoculation, K. F. Kellekman and T. II. Robinson ( U. 8. 

 Dept. Agr., Farmers' Bui. 315, pp. 20). — The main facts brought out in this bul- 

 letin are summarized as follows: " (1) Abundant nodule formation improves the 

 chemical composition as well as increases the quantity of a leguminous crop. 

 (2) Leguminous croi)s with noilules are more valuable as green manure than 

 leguminous crojis lacking nodules. (3) Nematode galls or root-knots resemble 

 nodules in ai)pearance. but they are very injurious and care should be taken not 

 to confuse the two growths. (4) It is wisest to depend upon pure cultures for 

 inoculating purposes. If soil is to be used, however, great precautions should 

 be taken in selecting and handling the soil to guard against the introduction of 

 weeds or plant diseases." 



Root action and bacteria, F. Fletcher {Xature [London], 16 {1901), Xos. 

 1968, I). 210 J 1911, p. 518). — These are brief notes referring to previous investi- 

 gations by the author, showing the excretion of toxic substances of an alkaloidal 

 nature by plant roots. 



The role of the oxidizing power of roots in soil fertility, O. Schreiner and 

 II. S. Reed (Jour. Biol. Chem., 3 {1901), Xo. 3, pp. XXIV, XXV; abs. in Chem. 

 Abs., 1 {1901), Xo. 11, p. 2259). — Evidence is adduced to show that roots pos- 

 sess well-deflued oxidizing powers, due principally to enzyms. Certain sub- 

 stances used as fertilizers promote the activity of roots, and root oxidation is 

 more active in fertile than in unproductive soils. 



The products of germination affecting soil fertility, O. Schreiner and M. X. 

 Sullivan {Jour. Biol. Chem.. 3 {1901), Xo. 3, pp. XXV, A'A'T7; abs. in Chem. 

 Abs., 1 {1901), No. 11, p. 2258). — Water in which seeds had germinated and 

 seedlings had grown apparently contained toxic properties which interfered 

 with the growth of a second crop in the same solution. Similar toxic properties 

 were observed in the juice expressed from seedlings. The juice was found to 

 contain cholin, xanthin bases, and soluble organic phosphorus compounds. 



Fertility of soils as affected by manures, F. D. Gardner (U. 8. Dept. Agr., 

 Bur. 8oUs Bui. 4^, PP- 59, figs. 5). — This bulletin "embodies the results of a 

 uniform scheme of manurial treatments, as measured by the resulting increase 

 in plant growth on soils collected from 2-20 fields in 23 States, located in the 

 eastern half of the United States." Ninety soil types were represented in the 

 experiments. 



