228 



DISCOVKRY 



description to assume that the L series have on tlie average 

 a critical quantum energy o-65 and the M series o-l2. 



Two questions now arise: (i) If the critical energy 

 4'67 represents, as is natural to assume, an energy given 

 up by the incident radiation to the atom, what becomes 

 of the balance when the radiation 4-55 or alternatively 

 4-02 is excited in the atom ? (2) If the energy of the 

 exciting radiation exceeds ^-Oy, what becomes of the excess ? 



The answer to the first appears to be supplied by the 

 observation that 4-67 — 4-55 =0-12 (M) and 4-67 — 

 4-02 = 0-65 (L). 



It seems to be the general rule, verified carefully by Duane 

 (Physical Review, December 1920), that the difference 

 between two critical quanta is equal to a wave quantum. 



An answer to the second question is given by de Broglie 

 (Comptes rendtis, March 29, 192 1), whose experimental 

 results agree -with, the hypothesis that the excess of the 

 incident quantum energy over the critical quantum 

 energy- appears subsequently as the energy' of a high-speed 

 electron. De Broglie examined (with other similar cases) 

 the magnetic spectrum of the electron radiation arising 

 from the incidence of rays characteristic of tungsten upon 

 a tin radiator. The two principal incident radiations had 

 quantum energies 10-62 and 9-40 ; they were, in fact, 

 the K lines of tungsten. In the magnetic spectrum were 

 found five groups of electrons ; one of these had a maxi- 

 mum energy 5-9 which is equal to 10-62 — 4-67 within 

 experimental error ; the maximum energy of the other 

 was 4-7, which is ver^- nearly 9-40 — 4-67. 



In this case, then, the difference between the energies 

 of the exciting quantum and of the critical quantum 

 is equal to the maximum energy of a group of electrons 

 which is found in the magnetic spectrum. 



Three other groups of electrons were found by de 

 Broglie on his plates. Their maximum energies were 

 4-4, 3-9, and 3-4. These were to be expected, since the 

 characteristic rays of tin, 4-55 and 402, were present, 

 having been excited by the tungsten rays of superior 

 quantum energ>', and, in further sequence to the rule just 

 stated, there ought to be electron groups haN-ing respectively 

 maximum energies equal to 4-55 — 0-12 = 4-43, 4-55 — 0-65 

 — 3-90, 4-02 — 0-I2 = 3-90, and 4-02 — 0-65 = 3-37. 



Parallel results in the case of X-rays have been obtained 

 by C. D. Ellis, under the direction of Rutherford. They 

 are described in the Proceedings of the Royal Society, 

 June 1921. 



OUR CONTEMPORARIES 

 The July Psyche (5s.) (the new and more ambitious form of 

 the original Psychic Research Quarterly) has some highly 

 interesting articles, notably Major Priestley's account of the 

 psychological difficulties of Antarctic E.xploration, illustrated 

 by personal experiences, the paper on ' ' Sleep " by Dr. Hartridge 

 and Mr. Whately Smith, and a note on the" Tudor-Hart Theory 

 of Colour." The last-named article touches on ground where 

 the account of "Revolutionary Movements in Modern Painting" 

 in the August issue of Discovery made a halt. The August 

 Geographical Journal contains a first instalment of an account 

 by Mrs. Rosita Forbes of her hazardous journey to the Kufara 

 Oasis. In Science Progress for July. Professor Bragg, of Man- 

 chester, writes on the dimensions of atoms and molecules, 

 and Dr. Atkins on Natural Indigo. 



Rural Japan 



By the Rev. Walter Weston, .\I.A,, 

 F.K.G.S. 



Lale British Chaplain at Yokohama 



Of all the poetic titles by which the Japanese in ancient 

 days delighted to designate their beautiful land, the 

 most ancient was that of Toyo-ashiwara-Mizitho-no- 

 Kitni — " the fertile reed-clad country- rich in grain." 

 In this we have the intimation that from the remotest 

 ages of the national existence it is agriculture that has 

 been the occupation of the majority of the people, 

 and their most fruitful source of livelihood. The 

 sudden emergence of modern Japan from her hermit- 

 like seclusion of former days into the roar and rush 

 of intercourse and competition with the Western world 

 has blinded the eyes of most passing observers to that 

 which forms the real basis of the national prosperity. 

 It is in the countr\'-side that we look upon the most 

 characteristic features of the life of the people, and the 

 traveller can only properly appreciate the real strength 

 of national organisation, and the most attractive 

 aspects of the national character, when he leaves the 

 crowded cities and the beaten tracks of Westernised 

 Japan for the fields and farms of the most intelligent 

 and hospitable peasantry in the world. 



In spite of the rapid progress of manufacturing and 

 mining industries in recent years, it is agriculture that 

 still stands first as the greatest means of the wealth 

 and power of the people of Japan. The rural popula- 

 tion number 60 per cent, of the whole, and it is they 

 who supply the Empire with neeirly all its food and 

 drink, and with the greater part of the raw materials 

 for manufactures. There are now no large landed 

 proprietors, and a feature of agriculture is that it means 

 the tillage of small holdings, not merely by the farmer 

 or the peasant himself, but with the help of sons, %vife, 

 daughters, and every member of his household. The 

 land really does belong to him, for the doctrine that all 

 is the property of the Emperor is a mere legal fiction, 

 and it is no wonder, therefore, that the man " on the 

 land " works as few peasantry in the world have ever 

 been known to work. Only about 12 per cent, of the 

 whole area of Japan is cultivable, and even this is not 

 naturally very fertile. It is only made to \ield its 

 utmost by the minutest and most careful system of 

 subsoil working, manuring, terracing and irrigation, 

 and these arc carried on with a care and thoroughness 

 that almost suggests gardening rather than farming. 

 There is practically no machinery employed, and nearly 

 all the work is done by hand, hoe and spade, helped 

 out at times by the o.\ or the horse. 



It is in the task of their subjugation of the land to 



