December 22, 1923] 



NA TURE 



891 



expansion of gases. They found that, when air issues 

 from a small orifice, a fall of temperature is experienced 

 amounting to half a degree Fahrenheit for each atmo- 

 sphere of difference of pressure between the two sides 

 )f the orifice. The great refrigerating industry thus 

 id its origin in the discovery of a purely scientific 

 iciple. 



It is the same with substances as with principles 

 id processes — they are first found as the result of 

 cientific research and are afterwards used, often after 

 long interval. The metal tungsten used for the fila- 

 lents of electric bulb lamps and thermionic valves was 

 scarcely known outside scientific laboratories a few 

 years ago. It was discovered about 1785, but its uses 

 were not understood until nearly a century later. It is 

 an essential constituent of high-speed tool-steels, which 

 require to be not only extremely hard but also to main- 

 tain their hardness at high temperatures, even at an 

 incipient red-heat. Tungsten steel is also used for the 

 permanent magnets of telephones and the magnetos of 

 every motor car and aeroplane. Manganese was in 

 existence long before it was made an ingredient of the 

 famous Hadfield steels, used for the helmets of British 

 forces during the War, armour-plates, tramway points, 

 and many other purposes. Chromium is used in the 

 making of stainless steel ; titanium, molybdenum, 

 nickel, vanadium, and other elements are similarly 

 employed to give special properties to steels, yet all 

 these elements were discovered by scientific investi- 

 gators without a thought of their practical value. 

 Thorium and cerium, used in the manufacture of in- 

 candescent gas mantles, of which about four hundred 

 millions are made annually, were products of the chemi- 

 cal laboratory many years before they gave rise to a 

 large industry ; and even the air-burner itself used for 

 such mantles and in all gas fires was first devised and 

 used by Bunsen for laboratory purposes. 



Every scientific discovery, however remote it may 

 seem at the moment from the ordinary practical needs 

 of life, may be the seed from which will grow a mighty 

 tree under which man will build his industrial tent. 

 When argon was isolated from the air in 1895, no one 

 regarded the discovery as of any practical importance, 

 yet the gas is now used in half-watt and other gas-filled 

 electric lamps as the most suitable for the purpose. 

 Neon, isolated from the atmosphere a little later, is 

 widely used for the brilliant pink glow lamps of illu- 

 minated advertisements, particularly in Paris, where 

 it is a by-product of the manufacture of liquid air. 

 Probably the most remarkable example of this kind is 

 afforded by the gas helium, which was detected in 

 the sun by Lockyer and Janssen in 1868, twenty-six 

 years later was extracted from cleveite by Ramsay, 

 and is now produced to the extent of thousands of 



NO. 2825. VOL. I 12] 



cubic feet daily from natural gas wells in the United 

 States for the inflation of dirigibles and other air-ships. 

 As it is non-inflammable and non-explosive, it has 

 decided advantages over hydrogen for this purpose and 

 is only slightly heavier. 



Before things can be used in any way they must be 

 discovered, and it is the particular function of science 

 to reveal them. It is the business of the scientific 

 investigator to discover, of the engineer or inventor to 

 recognise and apply the results achieved, of the artisan 

 to employ his skill in making them commercially profit- 

 able, and of the community to see that they are used to 

 promote social welfare. If the world has not been 

 made any happier by what science has given to it, the 

 fault is with the human race itself and not with science. 

 Happiness is a relative term, and no two individuals 

 have the same cup with which to measure it. The 

 beast in the field, or the pig in its sty, may be con- 

 sidered by some people as emblems of content, and if 

 these be the standards to use, then modern man may 

 envy the cave-dweller of prehistoric times. We cannot, 

 however, avoid progress, and whether this is accom- 

 panied by increased happiness or not depends upon 

 ourselves. We live in a beautiful world, yet how few 

 there are who find delight in it or raise their eyes to 

 the starry heavens above them. The gifts of God are 

 for those to enjoy who will, and the gifts of science may 

 likewise contribute to the uplifting of the human race 

 if they are rightly regarded, or its degradation if they 

 are not. The attitude of civilised man towards new 

 scientific knowledge at this epoch of the world's history 

 is that of a child playing with fire. It is necessary now 

 more than ever to teach him the strength as well as the 

 danger of the element in his hands, and to cultivate the 

 desire to make the noblest use of all things which are 

 granted to him through the achievements of workers 

 for the advancement of natural knowledge. When 

 this spirit prevails, the human race will prove itself 

 worthy of the opportunities which science gives for 

 social and spiritual progress, and man may indeed 

 become but a little lower than the angels. 



The Valuation of Mines. 



Mineral Valuation. By Prof. Henry Louis. Pp. 

 X + 281. (London : C. Griffin and Co., Ltd., 1923.) 

 155. net. 



THE principles underlying the valuation of mines, 

 whether for the purpose of sale or probate, the 

 raising of loans, investment, or taxation, are not so 

 fully comprehended, except by few mining engineers, 

 or so widely known as they should be. Consequently, 

 in the matter of actual valuations, judging from those 

 which have come before us, these principles are 



