August 23, 1883] 



NATURE 



393 



constitutes the surface, the thickness of which is the so- 

 called radius of molecular attraction. If the magnitude 

 of that radius were known, the average longitudinal ten- 

 sion per unit of area parallel to the surface in the outer 

 layer of liquid could be calculated. We hope before long 

 to apply several tests as to whether the thickness of a 

 black soap film is or is not less than twice the radius of 

 molecular attraction. Various considerations, the discus- 

 sion of which we defer, indicate that it is not mu r h less, 

 while if the size of an atom approaches Sir William 

 Thomson's lower limit it is probably much greater. If, 

 however, we assume that the thickness of the thinnest 

 film measured by us, say 7'2X io" 7 cm , was just equal to 

 twice the radius of molecular attraction, it follows that 

 the average stress parallel to the surface must be 

 2XS7/7"2Xio" 7 = i6x 10 s dynes per square centimetre. 

 This tension is eight times greater than that required 

 to tear brick or cement asunder (cf. Everett's " Units 

 and Physical Constants," p. 56), and one-half of that 

 required to tear cast tin. If the radius of molecular 

 attraction is the same for all substances, the stress in the 

 surface of mercury in contact with air must be nearly 

 ten times greater than in liquide glyceYique, or one-fifth 

 of the tension required to rupture steel bars. If the 

 radius is less than half the thickness of the black films, 

 these tensions would be greater. 



In many of the ordinary calculations on capillarity the 

 surface tension is treated as acting in a surface of infinite 

 tenuity. In reality it acts in the matter of a liquid shell of 

 small but definite thickness. Our experiments prove that 

 the average magnitude of the stress in this shell is at 

 least of the same order as that required to rupture the 

 less tenacious metals. A. W. Reinold 



A. W. RCcker 



JAPANESE LEARNED SOCIETIES 



NEARLY two years ago we described in Nature 

 a few of the principal of the scientific and learned 

 organisations which had sprung up in recent years in 

 Japan, in imitation of the societies of western countries. 

 The faculty for combination and organisation would 

 appear to be possessed in a high degree by the Japanese, 

 for on all hands we find them establishing societies for 

 political, self-help, philanthropic, industrial, commercial, 

 scientific, and literary purposes. The comparative in- 

 fancy of the press, and the consequent slowness and 

 difficulty of the interchange of ideas, have rendered these 

 organisations of great value in the social and political life 

 of the country. The extent to which they have spread 

 into every department of national life is well shown by a 

 paper recently contributed by Herr P. Mayet to the Trans- 

 actions of the German Asiatic Society of Japan, to which 

 we arc indebted for most of the facts in this article. 

 Societies for philanthropic and political purposes, though 

 probably more numerous and powerful than any others, 

 are entirely omitted as beside the .present purpose, 

 which is to show how the thirst for knowledge and re- 

 search is penetrating everywhere amongst this interesting 

 people. It is important, too, to note that these societies 

 are everywhere fostered and promoted by the leading 

 men of the country, including most of the Imperial 

 princes and the Ministers of State, and that they appear 

 to be due in all cases except one to native initiation, un- 

 assisted by foreigners. The exception is the Seismo- 

 logical Society, which owes its existence and its excellent 

 work to the efforts of Prof. Milne of the Engineering 

 College of Tokio. Recently, as we learn from Herr 

 Mayet, a Japanese section of this society has been 

 formed, with numerous native members, papers in 

 Japanese, and a native journal containing original as well 

 as translated contributions. Three of the societies at 

 present in existence have come down from ancient times. 

 These are the Numismatic and Archaeological Societies, and 



an association of Go players, similar to our own chess clubs. 

 A society for the protection and restoration of ancient 

 buildings, nearly all of which are naturally temples, has 

 recently been founded, with the energetic support of the 

 present Foreign Minister. As might have been expected, 

 there is a society for the cultivation of Chinese literature ; 

 but the more practical spirit of Young Japan is exhibited 

 in the association for propagating the employment of the 

 kana or syllabaries in Japanese literature. The import- 

 ance of the object of this society will be evident when it 

 is mentioned that a Japanese boy of the scholarly class 

 takes fr m five to seven years to learn the sounds of the 

 Chinese characters, and then he has to commence to 

 learn their meaning. Herr Mayet well observes that so 

 long as the Japanese youth are so heavily handicapped 

 in the race for knowledge they can hardly hope for vic- 

 tory against western lads, who, according to this writer's 

 estimate, are at twelve years of age nearly six years in 

 advance of the Japanese boy of the same age. To re- 

 move this obstacle by the employment of the system of 

 forty-seven syllables, now in use in books intended for 

 the common people, is the object of this society, which 

 has for president the Vice Finance Minister. Passing 

 over some art societies, we come to two intended for the 

 cultivation of the French and German languages respect- 

 ively. One of these is honoured by the support of an 

 Imperial prince. The French Society is working on a 

 French-Japanese dictionary, while both aim at the pub- 

 lication of translations from useful works in these 

 languages. Those hitherto published appear to deal 

 chiefly with political science, a study which appears 10 

 attract much of the energy and intellect of the rising 

 generation. A Statistical Society appears also to be very 

 successful, with its periodical publication. The Poly- 

 technic Association has for its object the extension of 

 knowledge with regard to mechanical inventions, and 

 their application to the increase of production in Japan. 

 Agricultural, dendrological, and forestry societies are also 

 in existence, and we may specially note, as a result of the 

 recent Fisheries Exhibition in Berlin, the establishment 

 of a society for the study and improvement of the 

 Japanese fisheries. Many of these associations are, it 

 will be observed, exceedingly practical in their aims, and 

 if the members can succeed in having their discussions 

 and researches circulated among the people, much good 

 will undoubtedly result. The Geographical Society of 

 Tokio has been frequently mentioned in these columns, 

 but there is also a Biological Society under the presidency 

 of the native Professor of Zoology in the University of 

 Tokio. Medical societies also are numerous, whether for 

 purposes of study or to afford aid and relief to the 

 indigent sick. The society for the collection and publi- 

 cation of books with regard to domestic industries must 

 be of much public utility. Of a more purely scientific 

 cast is the association for publishing a dictionary of 

 technical terms in various departments of science and the 

 mechanical arts. The process of finding these termini 

 technici is far from an easy one. They have to be ob- 

 tained from the Chinese, and have frequently, perhaps 

 generally, to be manufactured by combinations of the 

 Chinese ideographic signs, which often have but a strained 

 or fancied resemblance to the object to be named. 



In concluding his paper Herr Mayet says : " Our 

 glance at the Japanese societies of Tokio exhibits a 

 wealth of active ideal life and earnest endeavour. A 

 warm patriotic pulsation is perceptible everywhere, and 

 gives an assurance of the healthiness of the Japanese 

 popular mind. We have here, it is true, only the be- 

 ginning of association, but it promises much, and the 

 movement will undoubtedly be a constantly growing one." 

 After all, however, the ultimate value of any learned 

 society is measured by the work which it has done, and 

 we have as yet but little opportunity of applying this test 

 to the associations of Japan. 



