92 Proceedings. 



mercury In the eudiometer, and 2 cc. of oil of vitriol were 

 passed up to the top of the mercury. On passing sparks 

 from the coil the mercury steadily rose in the tube, until 

 after 35 minutes the liquid had risen to the wires, and only 

 5 cc. of the gases remained uncombined. Mr. Harcourt's 

 experiment can therefore be readily shown to a class during 

 a lecture. The experiment is really similar to that made 

 by Deville, who found that hydrogen and nitrogen had the 

 power of combining under the influence of the electric spark 

 in the presence of gaseous hydrochloric acid. Deville con- 

 sidered that the hydrochloric acid conferred the power of 

 combination on the hydrogen and nitrogen : no doubt the 

 hydrochloric acid in his experiment, as the sulphuric acid in 

 ours, removed the ammonia as it was produced, and pre- 

 sented the occurrence of the reverse change, viz. : — the 

 splitting up of the ammonia into its constituents. 



In Mr. Donkin's experiment the sparks of the "silent 

 discharge " were presumably of greater intensity than those 

 employed by us in 1877, for ordinary induction sparks bring 

 about a rapid combination, whereas our silent discharge 

 was ineffective. 



Dr. Schuster gave the results of some researches by 

 Prof Hann, of Vienna, and others, showing that the tem- 

 perature in the centre of an anti-cyclone is higher than on 

 its edge at heights above 1,500 feet, while at the sea level 

 it Is lowest in the centre. 



