FERTILIZERS. 733 



Forestry notes for Dubuque County, by T. H. MacBride. The articles on the geology 

 of the different counties deal with location, previous geological work, physiography, 

 stratigraphy, and economic geology, including mineral products, water supply, and 

 soils. Special attention is given to the loess and glacial drift soils of the Pleistocene 

 deposits of the different counties. 



FERTILIZERS. 



On the question of the preservation of manure and urine, 



J. KoNiG {VrtIJ8ch7\ Bayer. Landw. JEtaths.^S {1900), Su^). No. 3, 

 pj). 500-510). — The author briefly reviews the work of other investi- 

 gators on this subject and reports observations on the losses of nitrogen 

 in form of ammonia from solutions of ammonia, ammonium carbonate, 

 ammonium sulphate, and urine with and without access of air, and 

 with and without addition of phenol. The conclusion is reached that 

 the main precaution to be observed in preserving* manure from loss of 

 nitrogen is to exclude the air. Unless the air is excluded, preserva-, 

 five materials are of little value. The following practical rule, which 

 is shown to rest on a scientitic basis, is given: Protect the manure and 

 urine from air, sun, and rain, and apply in well-rotted condition to 

 soils kept open and well aerated by marling or liming. 



The method of making manure-preservation experiments, T. 

 Pfeiffek, F. MoszEiK, and O. Leivoiermann {Landw. TT/'.y. Stat., -5.^ 

 {1900), No. 5-6.) 2^P' 349-378). — The errors incident to such experi- 

 ments and means of overcoming them are discussed, the methods used 

 by the authors are described, and a series of experiments are reported. 



The contradictory results often obtained in laboratory experiments 

 on the preservation of manure are ascribed to the use of inaccurate or 

 dissimilar methods. Moreover, the results obtained in such experi- 

 ments can not be applied in practice without danger of serious error. 

 The authors have undertaken to devise a system of investigation Avhicli 

 reduces as far as possible the sources of error and makes the results of 

 more scientific and practical value. As a check on the determinations 

 of nitrogen at different stages they recommend the determination of 

 the income in food and outgo in excrement and animal product of the 

 nitrogen, phosphoric acid, and potash. The stud}' of the losses of 

 nitrogen nuist begin in the stall. Contradictory results have fre- 

 quently been due to variations in the amount of the easil}^ and diffi- 

 cultly decomposable nitrogen compounds. The difficulties pointed out 

 b}' Holdefleiss (E. S. R. , 11, p. 32) regarding the taking of samples, 

 correction for uneaten food, etc. , may be overcome by the use of the 

 balance of nitrogen and mineral matter referred to above. As 

 Maercker has shown, the preservation experiments should always be 

 accompanied b}^ fertilizer experiments. 



Experiments with 8 cows in two l-l-day series are reported. In one 

 series the manure remained under the animals 8 days, in the other only 



