28 



serious criticism. It is to be hoped that a larger number of manufacturers 

 will recognize the importance of this matter, for it is very important from the 

 consumer's standpoint, especially when he is asked to pay from S9 to $12 per 

 unit for nitrogen. 



It might be said, with reference to the Mapes' brands which have shown 

 inferior forms of organic nitrogen, that the company claims to have used only 

 guano, cottonseed meal, blood, tankage and bone to furnish the organic 

 nitrogen. 



The E. D. Chittenden Company claims the presence of some tobacco stems in 

 the brand of its goods, which shows a low activity of the water insoluble organic 

 nitrogen. It is a well-known fact that the water insoluble portion of Peruvian 

 guano and tobacco stems shows a low nitrogen activity. In case of the Peru- 

 vian guano this is no doubt due to the presence of more or less feathers and 

 indigestible organic matter; and in case of tobacco stems, the presence of an 

 exceptionally large quantity of woody fiber, accompanied by a correspondingly 

 low amount of nitrogen, would account for its low activity. Vegetation tests 

 made at this institution with the water insoluble portion of the nitrogen from 

 these two materials show a low activity corresponding to laboratory methods. 



Brands of Fertilizer showing Inferior Forms of Organic Nitrogen 



(Per Cent.). 



Note. — An availability below 50 by the alkaline and 85 by the neutral permanganate method classes the 

 water insoluble nitrogen as inferior. 



