INDUSTRIAL PROGRESS DURING THE YEAR 1876. cxci 



It would seem at first thought that the object might be attained by 

 using peat rich in sulphur or sulphur compounds, as iron pyrites ; but 

 a result of the oxidation of iron sulphide would be the formation of 

 protosulphate of iron, which would be injurious to vegetation. Zeit- 

 schrift des lamlwirthschaftliclien Central -Vereins der Provinz Sachsen^ 

 1876, L, s. 11. 



Oxidation of Nitrogen in its Compounds in the Soil. The experi- 

 ments above described had a further and more important object. 

 One of the most weighty questions which agricultural chemistry 

 has yet to solve is that of the changes which nitrogenous com- 

 pounds undergo in the soil. One part of the problem is the efiect 

 which various substances exert upon the oxidation of nitrogen in its 

 compounds. To gain some new light on this subject, determina- 

 tions were made of total nitrogen, nitric acid, and ammonia in each 

 mixture at the beginning and at the end of the experiment. In 

 general the nitrogen of the organic compounds evinced a very 

 marked tendency to become oxidized to nitric acid, stronger than 

 has been jDreviously noticed, from one half to two thirds of the 

 whole nitrogen being in some cases oxidized. The nitrification 

 was directly proportional to the amount of carbonate of lime pres- 

 ent. The nitrogen of the ammonia salts became oxidized with ex- 

 treme slowness, but was still oxidized to some extent in presence of 

 carbonate of lime. Potash salts prevented nitrification completely. 

 It is suggested that the failure of ammonia salts as manures in soils 

 poor in lime may be owing to the slow oxidation of the ammonia 

 to nitric acid, and that the poor eflfects sometimes observed with 

 potash salts may in some cases be due to their hindering the nitri- 

 fication of nitrogenous organic materials in the soil. Zeitschrift des 

 landw. Central -Vereins der Provins Sachseji, 1876, 1., s. 14. 



Nitrification Experiments hy Boussingaidt. Of interest in this con- 

 nection are some experiments on the same subject lately reported by 

 Boussingault, whose varied researches on the nitrogen of the atmos- 

 phere and soil in its relation to the nourishment of plants are al- 

 ready classic. The especial object of these last experiments was to 

 test and compare the effects of sand and lime (as carbonate), each 

 by itself, with that of a soil (loam), upon the formation of nitric acid 

 from the nitrogen of organic substances of animal origin used as 

 manure. Neither sand nor lime seemed by itself to favor especially 

 the formation of nitric acid, while a " sandy-clayey " soil, with only 

 0.02 per cent, of lime, promoted the oxidation of nitrogen very dQ- 

 cidedlj. Comptes-Pe?idiis, 1876, LXXXII., 477-479. 



At first sight, the results of Boussingault's experiments would 

 seem to be quite at variance with those of Holdefleiss, and witli the 

 common belief that lime in soils favors nitrification ; but it will be 

 observed that Boussingault's results refer to lime when used alone, 

 as carbonate of lime, while Holdefleiss worked with soils containing 



