( 810 ) 



radiation of light, or the heal must be the cause of the phenomenon. 



I then undertook the following set of experiments. 



A rod of antimonite quite covered by paraffin, and cut parallel 

 to the 6-axis, was shunted into the circuit of a dynamo, the tension 

 being kept at exactly 35 Volts by means of a resistance of incan- 

 descent lamps. When shunting- in the THOMSON-galvanometer *), which 

 had been hung up in an antivibration apparatus of Julius, and 

 which was so sensitive, that at a distance of mirror of two meters, 

 it still gave a deflection (double) of 26,5 mm. for a current of 

 0,000000006 Ampères, we obtained a constant, single deflection 



of L0, 7 cm. on the left of the zero point. 



An incandescent lamp (of 110 Volts), placed at about 2 meters' 

 distance from the preparation, gave an incr<'<ts<' of this deflection of 

 4 m.m., i.e. 3,7 % — agreeing in this case with a decrease of 

 resistance of about 53 millions of Ohms. 



When the same lamp was placed at 1 meter's distance it brought 

 about an increase of the deflection of 11 m.m.; at V, meter's distance 

 of about 20 m.m., and held near the rod for a short moment, of 

 more than 220 m.m., i. e. an increase of the conductivity of resp. 

 ±10%, ±18,7%, and 206%!') 



Then the lamp was removed, and after the deflection had resumed 

 about its original value, one of the curtains at the window was 

 drawn aside, so that the diffuse daylight (overcast sky) fell on the 

 apparatus. Instantly the deflection was increased by more than 4 m.m. 

 i.e. about 3,7%. Then a wooden box was placed over the apparatus, 

 and then removed. Every time the experiment was repeated the 

 constant deflections in the light were found from 3 to 8 m.m. larger 

 than those in the dark. 



§ 4. In the foregoing experiments only exceedingly little light 

 fell on the rod of antimonite, as it was quite covered by a coat of 

 paraffin 3 ) about 0,4 cm. thick, and so only the light penetrating 

 the half transparent coating could have any effect. 



Then the experiment was repeated as follows. 



A lamella 4 ) of antimonite was clasped between two much larger 

 copper plates, which two plates were well insulated. The condensator 

 (fig. 1) obtained in this way was suspended on silk threads. 8 ) 



1 ) The internal resistance of this instrument amounted to 6681 Ohms. 



2 ) The resistance of the rod was diminished by an amount of more than 950 

 millions of Ohms in the latter case. 



3 ) The purpose of these precautions will be explained later on in a paper 

 written in conjunction with Mr. Vas Nunes. 



*) The antimonite splits perfectly // (010), so j[ ö-axis. 



