and wound with about one hundred and thirty turns of moderately 

 thick insulated copper wire. The secondary coil (B), having six 

 thousand turns of fine copper wire, is quite separate from the primary 

 coil find slides in a groove in the wooden standard. In this way the 

 secondary coil may be brought over the primary coil or removed quite 

 a distance from it. 



As the coil (B) i^ removed from the coil (C) the amount of 

 induced current in (B) is decreased and when moved toward (C) the 

 current is increased. A centimetre scale about one metre in length 

 is placed beside the groove through which the coil (B) is moved, so 

 that the distance between the two coils (B) and (C) can be easily 

 measured. At one end of the primary coil is the so called Wagner 

 hammer (T) which "'makes" and "breaks" the primary current 

 about fifty times per second. The two poles of the buttery are con- 

 nected with the Wagner hammer by two binding screws which in 

 turn connect with the primary coil (C'). At each " make " and 

 " break " caused by the Wagner interrupter, an induced current is 

 set up in the coil (B), from which it may be conducted off by con- 

 necting wires to the binding posts at the end of coil (B). At (D) 

 Figure I is shown a key by means of which a short circuit may be 

 formed. 



In some of the experiments, hourly treatment was desired. This 

 was accomplished by passing the wires from the batt* ry toan electiic 

 clock and thence to the iuchiclion machine. Each hour, the clock 

 formed a connection completing the circuit and a current was 

 passed through for a period of about thirty seconds. 



METHODS OF APPLYING THE STIMULATION. 



In experiments given in tables I — XVII, the apparatus represented 

 in Figure 2 was used. Thisconsisted of two glass cylinders, a larger 

 one about two inches in diameter for large seeds and a smaller about 

 three fourths of an inch in diameter for those of less size. Within 

 these cylinders, thoroughly moistened seeds were i)laced and the 

 openings closed with copper discs having wires attached. By means 

 of these wires the discs were connected with the poles of the induc- 

 tion coil and a current passed through, the moist seeds making a 

 good conductor. After the seeds had been stimulated by passing 

 the current through them they were placed in germinating pans as 

 sliown in figure 5. 



