APPENDIX 277 



in the position shown (Fig. 174). The height to which 

 the water rises is then noted, after which the seeds are 

 dropped into the test tube, and the top of the cylinder is 

 jarred slightly by tapping it with a pencil. The height 

 of the water is again noted, when the difference in the 

 readings indicates the weight of the seeds in grams. 



The test tube should float in the center of the cylin- 

 der, as shown, and the readings should be taken with 

 the eye on a level with the surface of the water. 



Each student (or pair of students) is provided with 

 the apparatus shown in Fig. 174, and with two bottles 

 of at least 100 cc. capacity, with corks. Each bottle 

 should have a strip of white paper pasted vertically 

 upon it to receive the name of the student and other 

 data. 



Each student weighs or measures the volume of 50 

 fresh seeds of the bean, pea or Indian corn in the man- 

 ner described above. Having noted the weight or vol- 

 ume in his notebook, he pours the seeds, with the water, 

 into one of his bottles, corks the latter and writes his 

 name, with the date, on the paper pasted on its side. 

 He then repeats the process with seeds of the honey 

 locust, yellow wood or some other seed that does not 

 readily absorb cool water, and after recording the data 

 in his notebook, places the bottles in a warm place until 

 the following day, when he again determines the weight 

 or volume of the two kinds of seeds. The seeds placed in 

 the first bottle will usually be found to have nearly or 

 quite doubled in size, while those in the second bottle 

 have scarcely swollen at all. 



Next, show the class a sample of the second lot of 

 seeds that have fully swollen from soaking in hot water. 

 Impress upon their minds the fact that while most seeds 



