MODERN' CHl•:MrSTR^•. 211 



considerations, that, at a height of over sixty miles, tlie earth's 

 atmosphere consists ahnost entirely (99.5 per cent.) of hydrogen, 

 with a little ( .5 per cent. ) helinm. Then, again, the energy 

 produced in the formation of a single pound of water from 

 oxygen and hydrogen is represented as sufificient to hurl a man 

 to a height of over seven miles. The author's occasionally 

 whim>ical way of putting things has the effect of impressing 

 scientific facts on the mind more indelihly than the usual 

 conventional method can achieve. When dealing with sulphur 

 Dr. ^lartin subscrihes to the view that on the moon enormous 

 deposits of sulphur exist, probably immensely exceeding an}- 

 which occur on our earth, inasmuch as sulphur, the almost 

 constant concomitant of volcanic action, will inevitably be found 

 in the mighty lunar craters of over 100 miles across, where the 

 sttipendous scale of volcanic activity of past ages reduces the 

 greatest similar terrestrial displays within historic times to abso- 

 lute insignificance. The scientific imagination to which Prof. 

 Ostwald referred frequently shows itself in the course of the 

 book. At one time it is the description of a planet possessing 

 great indigo-blue seas of ozone, with blue clouds and mists of 

 ozone ^'apour in a dark blue sky. and possibly even a blue 

 sun : at another it is seen in the portrayal of the final stages 

 of our own earth, when all its atmosphere will have gone, and 

 bergs of solid air float from the poles towards the equator, in 

 seas of liquid air ; when all sound has ceased, and stars at midday 

 shine out of a coal-black sky upon a lifeless world. The volume 

 closes with a chapter on fire, flame, and spectrum analysis, in the 

 course of which the following incidental remarks occur : — 



" It is no accident that those nations which lead in scientific re- 

 search soon lead in everything else, be it wealth, trade, war, or peace. 

 It is therefore much to be regretted that in England chemical research 

 is greatly discouraged by a miserable system of public examinations which 

 divert the energy of our rising youth, not into discovering new facts, 

 but into al^sorbing by bookwork facts already discovered by others. . . . 

 How different a system is employed for training the youth in Germany 

 and America ! In these countries chemical research pays the student in 

 that it helps him to attain his diploma and obtain a post afterwards 

 in which he can earn his living. He can do research while actually study- 

 ing for his degree — a thing quite impossible to do in England because 

 of the incessant examinations, intermediate and other, which are always 

 looming on his mental horizon. The German student . . . usually 

 spends his time in mental peace, doing research work under a dis- 

 tinguished professor as well as studying and attending courses of lectures 

 to qualify for his final examination. The final result of this system is 

 seen in the magnificent and flourishing chemical industry of that .great 

 country." 



Amongst those whom the author thanks for assistance rendered 

 in the publication are Sir William Crookes, Mr. F. Soddy, Mr. 

 J. E. ( iore. and Sir William Ramsay. 



