AIDS IN IDENTIFICATION OF WOODS 



737 



case of Pterocarpus indicus. The method used for detecting fluores- 

 cence is as follows : Take a few grams of wood chips and put them 

 into an ordinary test tube with water, leaving them for about two 

 weeks or more, during which time the water usually becomes more or 

 less colored. After sufficient extraction filter off from the chips and 

 examine. If the fluorescence of the extract is very strong it can be 



G 



Fig. 1. — Apparatus for detecting fluorescence in water extracts. A, eyehole ; 

 B, lens ; C, sunlight ; D, test tube. 



detected even in the open room ; if not, special apparatus will be needed. 

 This purpose is served by a small camera box roughly made of wood 

 with an opening in the top to admit the test tube, a small lens in one 

 side, and an eyehole in another at right angles to it as indicated in the 

 figure 1. Place the tube in the camera, let the sunlight coming through 

 the lens fall directly on the extract and observe any fluorescence by 

 placing the eye close to the peephole. The fluorescence is generally 

 intensified by adding ammonia solution, but in some cases it disappears. 

 In the following table (***) indicates pronounced fluorescence evident 

 in the open room, (**) more clearly visible in camera, and (*) detected 

 onlv bv camera. 



LITERATURE 



(1) K. Shibata, I. Nagai, M. Kishida. The occurrence and physiological sig- 

 nificance of flavone derivatives in plants. Biochemical laboratory, Department of 

 Botany, Tokyo Imperial University, 1916. 



(2) R. Kanehira. Anatomical characters and identification of Formosan 

 woods with critical remarks from the climatic point of view. Bureau of Pro- 

 ductive Industries, Government of Formosa, 1921. 



(.3) AI. Fujioka. Report of Forest Experiment Station, Bureau of Forestry, 

 Department of Agriculture and Commerce, No. 15, 21. 



