SOILS FERTILIZERS. 623 



for judging of the moans of improving (rendering allialine) a sick soil, the hot 

 alcohol extraction method is best. 



Chemical and bacteriological factors in the ammonification of soil nitrogen, 

 J. G. LiPMAN {yew Jersey Stas. Rpt. 1906, pp. 119-187). — This article reports 

 a series of experiments with nutrient solutions consisting of Witte's peptone, 

 gelatin, or egg albumen, with the addition of the ordinarj^ mineral salts, and in 

 some cases, mannite, which were inoculated with infusions of soils of different 

 kinds and previous treatment, or with pure cultures of common soil organisms. 



The progress of ammonification was ascertained by determining the ammonia 

 in the cultures from time to time, usually at intervals of from 3 to 6 days. 



The results obtained under a variety of conditions are reported and discussed 

 in detail. They indicate in general that the ammonifying organisms are unequally 

 represented in different soils and that the addition of salts to the nutrient 

 solution promotes their activity. In some cases the bacteriological factor 

 appeared to predominate over the chemical, although the chemical composition 

 of the soil was apparently very important. It was found "that, under the con- 

 ditions of the experiment, the bacteriological differences developed in initially 

 identical soil by varying fertilizer treatment are brought out clearly and con- 

 sistently, whether soil infusion or the soil itself is used as inoculating mate- 

 rial." It was also found " that the new samples were much superior to the old 

 in their power of ammonification, and likewise, that the direct soil inoculations 

 led to the production of more ammonia in the culture solution than was true of 

 the corresponding soil-infusion inoculations." 



In experiments with Azotobacter growing in nutrient solutions containing 

 mannite data were obtained which showed that " different soils may give up 

 mineral salts to mannite solutions, with which they are in contact, in quantities 

 iarge enough to supply the needs of vigorously growing Azotobacter cells. . . . 

 The growth of the Azotobacter organisms in the mannite solutions, the forma- 

 tion of carbon dioxid in accompanying this growth, and the presence of the 

 mannite itself, each exerted a certain effect on the solution of the soil phos- 

 phates. The soils which yielded the greatest amount of phosphates to the 

 mannite solution allowed also the most vigorous development of the bacteria. 

 On the other hand, the solutions which contained the organisms growing most 

 vigorously parted most rapidly with their phosphates, and thereby hastened the 

 further solution of the soil phosphates. For this reason there was proportion- 

 ately and absolutely more Azotobacter growth in the mannite solutions contain- 

 ing larger amounts of phosphates of greater initial solubility." 



A method of determining the mineral i-equirements of soils based upon these 

 facts is outlined. 



Losses of ammonia from culture solutions, J. G. Lipman, and P. E. Brown 

 (Jour. Amer. Vhcm. aS'oc, 29 (1907), No. 9, pp. iJ58-i56'2).— Determinations of 

 ammonia were made in sterilized and unsterilized Omeliauski culture solutions 

 immediately after preparation and after having been kept in an incubator 6, 

 12, and 24-25 days. Large losses of ammonia occurred as a result of steriliza- 

 tion as well as on keeping the sterilized solution in the incubator at a tempera- 

 ture of 2H° C. 



In the first series of experiments reported the sterilized solution lost about 

 three-fifths of its ammonia in 24 days. In a second series of experiments, in 

 which calcium carbonate was substituted for magnesium carbonate in some 

 of the tests, it was found that while the magnesium carbonate solutions lost 

 considerably more than one-half of their ammonia nitrogen in 25 days, the cal- 

 cium carbonate solutions lost scarcely more than one-eighth of the initial 

 amount. In calcium carbonate solutions inoculated with soil infusion a small 



