1912. 



PUBLIC DOCUMENT — No. 31. 



27 



and ti liirge pipcstem triangle was placed across the top of 

 each dish npon which was set a smaller crystallization dish 

 containing", in each case, 100 grams of one of the absorbents. 

 Each crystallization dish thns arranged was set on a gronnd- 

 glass plate and enclosed within a bell glass, which was made 

 air-tight bv the use of tallow and sealed with melted paraffine. 

 The tests were conducted side by side in a room of ordinary 

 temperature (70° to 75° F.) and covered a period of six 

 weeks. At the close of the experiment all of the chemicals 

 were subjected to a chemical analysis, and showed the follow- 

 ing content of nitrogen : — 



2''able 2. — Weight of Nitrogen in Manure and Nitrogen absorbed by Each 



Chemical. 



From the above table of comparative results it will be seen 

 that magnesium sulfate absorbed the greatest amount of nitro- 

 gen, and that gypsum, the absorbent more commonly used in 

 general farm practice, had the lowest nitrogen absorption power 

 of any of the chemicals under trial. The percentage of nitro- 

 gen absorbed, however, in proportion to the amount contained 

 in the manure was so small (less than 1 per cent.) as to indi- 

 cate that but little decomposition took place. This is not to 

 be wondered at when it is recalled that the manure was placed 

 in an air-tight dish. 



To obtain further data as to the nitrogen-absorbing capacity 

 of the different chemicals during the process of decomposition 

 of barnyard manure, another test was instituted, beginning on 

 the same date as the above-described experiments and contin- 

 uing through a period of six weeks. Four hundred and fifty 



