UNDER this title, the Japan Mail describes a curious Society, established in Japan, in honour of Isaac Newton, and which is not a new scientific association so much as a new cult. The day of all the year to the members is Christmas Day, being that on which in 1642 the immortal Newton was born. The constitution is of the simplest. The professors, graduates, and students of the mathematical, astronomical, and physical classes of the Tokio University are ex officio members; once a member always a member; and there are no others. The Society was launched as one for undergraduates by Messrs. F ajisawa, Tanaka, and Tanakadate, the first brilliant triumvirate of mathematical graduates which the P okio University gave to the world. In its early days it met in the students' dormitory. Bat as the undergraduates developed into graduates and assistants, the professors themselves were drawn into the fold, and a more suitable assembly hall was found in the University Observatory. Now, however, that building is devoted to seismological pursuits. At Christmas, 1890, or Newtonmas, 248, for the first time, the members of the Newtonkai, or Newton Association, met in the Physical Laboratory of the Imperial University, to hear each other talk, to distribute appropriate gifts, and to lengthen out the small hours with laughter and good cheer. The Society has no President: a portrait of the august Sir Isaac presides over the scene. It keeps no written records, no minutes;, but its traditions are simple, and easily handed down from year to year. The entertainment provided is the work of the second-year students, assisted by those of the first year. Each professor is expected to make a little speech, which is sometimes historical, sometimes whimsical, as the individual spirit may prompt; but it must not be suggestive of the background of a blackboard. The meeting in fact is essentially social; and in the preparation of the magic lantern slides, the committee of management lay themselves out for frolic and jest. The picture may represent a comical incident familiar to most of the members, or it may be a pictorial conundrum to guess. It was a fine humour, for instance, which gave a caricature of one student notorious for his indefatigable asking of questions. This youth was shown labouring under a shoulder beam, from which hung two buckets filled to overflowing with points of interrogation; while in the background was seated one of the professors, perfectly aghast as this mathematical labourer approached with his load. After the magic lantern exhibition comes the lottery for presents. This is a great feature, productive of much merriment. Each person draws a paper, which may be blank, but usually has a name on it. This name may be one of the illustrious living, or the still more illustrious dead. Corresponding to each name is an article, which, with all solemnity, is presented to the holder of the paper. The connection between the article and the name is more or less symbolic, or it may rest on a far-fetched pun, to which the Japanese language readily lends itself. Usually the jokes are very technical; but occasionally they appeal to a circle more wide than mathematical. Thus the drawer of “Newton” got an apple, and the drawer of “Franklin” a kite. “Herschell” (Sir John) was represented by a sprig of Nanten (“southern heavens,” which he surveyed); “Archimedes,” by a naked doll supposed to be returning from the bath; while the holder of “Kant-Laplace,” got a puff of tobacco smoke blown in his face, symbolic of the nebular hypothesis. Some time ago it was pointed out by a European member of the Kai that in holding the “Newtonmas” on Christmas Day the members were guilty of a chronological crime hardly to be excused in men trained in the accurate school of Newton. For although he was registered as being born on Christmas Day, 1642, it was Christmas Day, old style. In all strictness he was born on January 5, 1643. But the great convenience of having the fête at the beginning rather than towards the end of the winter vacation, and the avoidance of clashing with Japanese New Year festivities, were sufficient to outweigh all other considerations whatsoever. Besides, did not Newton himself hold his birthday on Christmas Day? Why, then, should his admirers hold it on any other? After all, concludes the Yokohama journal, the peculiar interest of the “Newtonmas” lies in its existence. Only to the hero-worshipping Japanese has it occurred thus to pay honour to the memory of the greatest mathematical sage of all time. Very few English-speaking naturalists, to use the word in its widest and legitimate sense, are even aware that Christmas Day in 1642 beheld the birth of Newton. It is possible that nearly fifty years ago a bicentenary fête was held in Cambridge; and it is very probable that about fifty years hence Newton's tercentenary will be celebrated in England— perhaps over all the civilized world. But an annual celebration by a Newton Club outside Japan is a thing not to be dreamed of, unless Japan influences the hero-worshipping instinct of the Western people as profoundly as she has influenced their æsthetic taste.