No. 5. DEPARTMENT OF AGRICULTURE. 115 



To meet the demand for such information, as expressed in resolu- 

 tions adopted by the State Board of Agriculture, the most practic- 

 able way has seemed to be the application of a chemical method re- 

 cently devised for the purpose. The principle of this method is set 

 forth in the following paragraphs prepared at the request of the de- 

 partment by Dr. William Frear, Chemist to the Pennsylvania Agri- 

 cultural Experiment Station, by whom the analysis of fertilizers is 

 made. 



''When a fertilizer is extracted by water, its most immediately 

 available nitrogenous substances are removed. Water dissolves the 

 nitrates, sulphate of ammonia, more or less of the nitrogen of the 

 high grade organic materials, such as dried blood, most of the nitro- 

 gen of cyanamid, and a portion of the nitrogen from wet-mixed or 

 acid,treated hair, leather, wool-waste, etc., but very little, if any, 

 from the low grade materials last named, when present in unacidu- 

 lated state. 



"When dried blood, animal tankage, and fine ground bone are left 

 in contact with field soil, the soil organisms quite rapidly transform 

 most of the nitrogenous material over into ammonia and nitric acid. 

 The same changes freely occur when properly acidulated leather, hair 

 or wool-waste is exposed in the soil to the action of these organisms. 

 Whereas, the action of the soil organisms upon the hair, raw or rotted, 

 wool-waste and leather, raw, steamed or roasted, is very slow. 



''The members of the Association of Official Agricultural Chemists 

 of North America have, for years, been trying to find a chemical 

 method by which, in the course of an hour or two, the degree of ac- 

 tivity of the soil organisms upon these substances during a growing 

 season is paralleled. Among the methods tried is that proposed by 

 Prof. C. H. Jones, of the Vermont Agricultural Experiment Station. 

 The New England and New Jersey Experiment Stations have adopted 

 this method for use in their several states. The method depends upon 

 the fact that under certain definite conditions of analytical procedure, 

 alkaline potassium permanganate much more largely decomposes the 

 water-soluble portions of the nitrogenous materials of dried blood, 

 animal tankage, fish, horn meal, and the like, than it does the water- 

 insoluble materials of hair, wool- waste, hoof parings, leather, peat 

 and garbage tankage. The nitrogen is split off in the form of am- 

 monia, which may be recovered by distillation and its quantity de- 

 termined. The significant fact is not the quantity of ammonia thus 

 formed, for this differs greatly among highly available materials ; but 

 the proportion which the quantity of nitrogen is the residual resist- 

 ant material bears to the total water-insoluble nitrogen. The differ- 

 ence of this kind are well shown in analyses recently published by 

 Jones.* 



*Jour. Industrial and Engineering Chemigtrj, i (1*18) , itl-Hl. 



