PROBLEMS OF CHEMISTRY 315 



know of chemistry at these temperatures. He has made 

 use of a simple contrivance, which he calls an electric 

 furnace. In this he has subjected many things to tem- 

 peratures as high as from 6,000 to 7,000 degrees Fahren- 

 heit. It is a pity that Dante could not have taken a course 

 in chemistry under M. Moissan. These temperatures, not- 

 withstanding their great height, are suggestive of the lower 

 regions. This work has opened up a new world to chemists, 

 and has shown them that there are many unsolved prob- 

 lems to be found here. Things that unite readily at ordi- 

 nary high temperatures do not act at all at these higher 

 temperatures; and things that do not act at all at the 

 former act vigorously at the latter. There is no end of 

 what may be learned in this new field. 



Just as it is desirable to know how things act upon one 

 another at high temperatures, so it is equally desirable to 

 know how they act at low temperatures. Curiously enough, 

 work in this direction has kept pace with that in the oppo- 

 site direction, referred to in the last paragraph. Within 

 the last year or two, the attention of everybody has been 

 directed to low temperatures by the interesting work that 

 has been done on liquid air. It is well known that air can 

 now be liquefied on the large scale, and that liquid air is 

 an article of commerce. This brings low temperatures to 

 our door, for it is only necessary to expose the liquid in an 

 open vessel to produce a temperature of about 300 degrees 

 below zero, Fahrenheit ! Then, further, Dewar has recently 

 succeeded in liquefying and, indeed, solidifying hydrogen 

 a much more difficult feat than liquefying air and with 

 the solid thus produced he has reached the temperature 

 432 degrees below zero, Fahrenheit! There is no serious 

 difficulty then, at present, in studying chemical action at 

 temperatures in the neighborhood of 300 degrees below 

 zero. The first results are not reassuring. Things are not 

 very lively down there, to say the least. It may be that 

 all chemical action ceases below a certain temperature, but 

 we do not, as yet, know enough about this subject to justify 



