212 Graphic Methods in Teaching. [20 



saucers or shallow dishes holding sufficient water to keep 

 them just covered. There are now two elements to be 

 considered the temperature and the presence of moist- 

 ure. Observations were made at precisely 7 A. M. and 

 9 P. M. and a record made of the temperature and the 

 condition of the seeds. This was continued for seven 

 days. New facts were obtained from this experiment. 

 The seeds swell and seem to begin to germinate, but at 

 the end of the seven days the seeds are apparently dead 

 and even beginning to decay. The new facts obtained 

 are these: Moisture causes seeds to swell as if about to 

 germinate, but under the influence of a low temperature 

 they die and decay. 



Ten more seeds of each kind are selected and placed in 

 the oven of a stove in a dry vessel, and a thermometer is 

 placed in the oven to ascertain, as nearly as may be with 

 an ordinary glass, the temperature in which the seeds are 

 now placed. Observations are now made every thirty 

 minutes and new facts are obtained. A high temperature, 

 in the course of an hour or more, will burn and destroy 

 the seeds and render them lifeless and incapable of 

 germination. The pupil now sees that a low temperature 

 has no effect on dry seeds and that a high temperature 

 burns and destroys them. Ten more seeds are selected 

 and placed in saucers with water as before and put in the 

 oven. Observations are made every thirty minutes and 

 in an hour or two the seeds are cooked and lifeless. A 

 high temperature is therefore fatal to the seeds whether 

 they are wet or dry. Ten more seeds are again selected, 

 placed in saucers with water and placed in a dark closet 

 where the temperature is 70. Observations are then made 

 at 7 A. M., at 3 P. M., and at 9 P. M., and a record made 

 of the condition of the seeds at each observation. A 

 record is also made of the temperature to note any varia- 

 tions. Wholly new effects are now observed. The seeds 

 swell and germinate, one group after the other, and at 



