156 MODERN SCIENCE READER 



ing this, we will pass to 'the consideration of another, 

 entirely different and yet important, class of apparatus 

 and processes. 



II. Electric Arcs and Discharges in Gases 



Electric arcs and high-tension discharges through gases 

 are capable of producing some chemical compositions and 

 decompositions which are very useful, and profitable to 

 operate. This is a branch of electrochemistry which has 

 not been as thoroughly studied as some others, its phe- 

 nomena are not as thoroughly under control as electrolysis 

 and electro-thermal reactions, and its possibilities are not 

 as thoroughly understood or utilized. 



Ozone is being made from air by the silent discharge of 

 high-tension electric current. The apparatus is so far 

 simplified as to be made in small units suitable for house- 

 hold use, ready to attach to a low-tension alternating cur- 

 rent supply. The uses for the ozone thus produced are 

 particularly for purifying water and air ; it makes very 

 impure water perfectly safe to drink, and purifies the air 

 of assembly halls and sick-rooms, acting as an antiseptic. 

 According to all appearances, this electrochemical doubling 

 up of oxygen into a more efficient oxidizing form is devel- 

 oping into a simple and highly efficient aid to healthy living. 



Nitric Acid is an expensive acid made from the natural 

 alkaline nitrate salts, such as Chili saltpeter. These 

 nitrates are the salvation of the agriculturist, for they 

 furnish the ground with the necessary nitrogen which 

 plants can assimilate. The Chili "nitrate kings" have 

 gained many millions of dollars, even hundreds of millions, 

 in thus supplying the world's demand for fertilizer. But, 

 electrochemistry has another solution to this problem, which 

 is rapidly rendering every country which adopts it inde- 

 pendent of the foreign fertilizer. The air we breathe con- 

 tains tmcombined nitrogen and oxygen gases, which if 

 combined and brought into contact with water furnish the 

 exact constituents of nitric acid. The way to do this has 



