No. 5. DEPARTMENT OF AGRICULTURE. 445 



ials, among whicli, from its behavior with this treatment, must be 

 included horn meal, the percentage of inactive nitrogen in the insolu- 

 ble nitrogen is usually under 40 per cent.; and the ratio of inactive 

 to active insoluble nitrogen in such materials is usually less than 

 60:100. On the other hand, in the case of low-grade nitrogenous ma- 

 terials, the proportions of inactive nitrogen are much higher. The 

 separations effected by these methods are therefore of great value 

 in distinguishing whether the insoluble nitrogen is derived from high 

 grade materials, or from low grade substances such as garbage tank- 

 age, peat, mora meal, unacidulated hair, leather, etc. There is, 

 however, one fertilizer ingredient rapidly coming into use, whose 

 presence may lead to erroneous conclusion, if judgment is based 

 solely upon the facts ascertained by the foregoing method, namely, 

 cyanamid. This substance contains from 13 to 16,5 per cent, of ni- 

 trogen, of which 12 to 14.7 per cent, is soluble in water, by the mode 

 of treatment used in the alkaline permanganate method; and, of the 

 1.0 to 1.7 per cent, of water-insoluble nitrogen, less than one-fifth is 

 active; so that the ratio of inactive to insoluble nitrogen is about 

 80:100. Owing to its tendency to reduce the availability of the 

 phosphoric acid in acid phosphate mixtures, limited quantities only 

 of this ingredient can be used advantageously in mixed fertilizers. 

 Nevertheless, in cases where low grade sources of nitrogen are in- 

 dicated by the foregoing method, it would be needful to determine, 

 by supplementary tests, whether or not cynamid may be present to 

 account for an undue proportion of inactive, insoluble nitrogen, 

 before concluding that such excess of inactive nitrogenous material 

 is attributable to low-grade nitrogenous constituents. It is desir- 

 able to keep in mind at this point the fact also that certain widely 

 used low-grade nitrogenous substances, such as garbage tankage, 

 peat and mora meal, are not included in the list of substances whose 

 presence requires specific declaration under Section 4 of the Fertilizer 

 Act. (5) CHLORIN — this determination is made to afford a basis for 

 estimating the proportion of the potash that is present as chlorid 

 or muriate, the cheaper source. The computation is made on the 

 assumption that the chlorin present, unless in excess, has been in- 

 troduced in the form of muriate of potash; but doubtless there are 

 occasional exceptions to this rule. One part of chlorin combines 

 with 1.326 parts of potash to form the pure muriate; knowing the 

 chlorin, it is, therefore, easy to compute the potash equivalent thereto. 

 (7) In the case of ground bone, the state of sub-division is deter- 

 mined by sifting through accurately made sieves; the cost of pre- 

 paration and especially the promptness of action of bone in the soil 

 depend very largely on the fineness of its particles, the finer being 

 much more quickly useful to the plant. 



The legislation of 1909 has made needful, some additional tests. 

 Section 4, of the Act of May 1, 1909, prohibits the sale of "pulverized 

 leather, hair, ground hoof, horn, or wool waste, raw, steamed, 

 roasted, or in any form, as a fertilizer, or as an ingredient of a fer- 

 tilizer or manure, without an explicit statement of the fact." All 

 nitrogenous fertilizers have, therefore, been submitted to a careful 

 microscopic examination, at the time of preparing the sample for 

 analysis, to defect the presence of the tissues characteristic of the 

 several materials above named. The act of April 23, 1909, makes it un- 

 lawful to use the word ''bone" in connection with, or as part of the 



