102 The Philippine Journal of Science isie 



the upper layer of the soil deprive it of nearly all the available 

 moisture during the dry season. The removal of the grass for 

 the purpose of reforestation is impracticable, because of the cost, 

 and few trees are able successfully to compete with the cogon. 

 Ipel, however, can thrive under these conditions, and owing to its 

 habit of growing in thickets, soon chokes out the grass. Other 

 trees can be successfully grown among the ipel. Indeed the 

 presence of ipel is an advantage, since it serves as a shade to the 

 young tree and raises the height at which the tree sends out 

 branches. 



While ipel is not so valuable a firewood as the bacauans (the 

 mangrove trees), yet, in the growing scarcity of these and the 

 demand for a quick-growing firewood for sugar centrals, etc., its 

 value here will eventually increase. 



Another factor worth considering is the improvement of the 

 soil brought about by the cultivation of ipel. Since it belongs 

 to the legumes, it possesses the property common to the members 

 of this family of fixing the nitrogen of the air and making it avail- 

 able for plant growth. The shrub, or small tree, grows to a 

 height of from 2 to 6 meters, in rare cases 10 meters, and bears 

 thin, flat pods, from 12 to 18 centimeters long, within which are 

 from fifteen to twenty-five small, shining, flattened brown seeds 

 about 8 by 4 by 1.5 millimeters in dimensions. 



These seeds when roasted and ground produce a reddish brown 

 powder, having a color very similar to that of coffee and with an 

 odor somewhat resembling the aroma of coffee. The odor of the 

 infusion with water resembles the odor of coffee more closely 

 than does that of the ground, roasted bean. This infusion is 

 brown by direct light and has a deep green fluorescence by re- 

 flected light. It gives a violet color, but no precipitate with fer- 

 ric chloride solution ; with solutions of potassium-mercurio-iodide, 

 potassium hydroxide, picric acid, iodine-potassium iodide, tannic 

 acid, and Fehling it gives no precipitates. When warmed first 

 with hydrochloric acid and then tested with Fehling's solution, 

 it gives a precipitate of reduced copper oxide. Copper acetate 

 produces a greenish brown, gelatinous precipitate with a dark 

 green, supernatant liquid. Lead acetate gives a brownish yellow, 

 gelatinous precipitate. The infusion is slightly acid to litmus 

 and gelatinizes albumen. 



Graham, Stenhouse, and Campbell proposed to take the density 

 of different infusions of coffee and adulterants as a guide to the 

 adulteration. They gave the following data for solutions made 

 by treating the substance with ten times its weight of cold water, 

 boiling, filtering, and then determining its density at 60° F. 



