June 9, 1898] 



NATURE 



LETTERS _ TO THE EDITOR 



[The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of rejected 

 manuscripts intended for this or any other part ^NATURE. 

 No notice is taken of anonymous communications.^ 



Liquid Hydrogen. 



The letter of W. Hampson, which appears in your issue of 

 May 26, can only mean by implication to charge me with having 

 utilised without acknowledgment an idea of his, conveyed through 

 a third party, in my paper on the liquid hydrogen jet, published 

 in 1895. Such a suggestion is absolutely without any found- 

 ation in fact. My results would have been attained had Dr. 

 Hampson never existed, just as they have been developed. He 

 certainly in no way contributed directly or indirectly to the 

 success of those hydrogen experiments. Had Mr. Hampson 

 attempted to consult me as to his plans, I should have 

 declined to entertain them, just as I had treated, under similar 

 circumstances, distinguished colleagues engaged in low tem- 

 perature research ; for no other reason than to avoid the possi- 

 bility of controversy. Further, I never would have allowed my 

 assistant either to consider or advise on the projected scheme 

 of some other person about to engage in the same field of in- 

 vestigation, simply because such a position would be quite un- 

 precedented, and certain to result in misunderstandings. W. 

 Hampson is the only inventor or investigator who has not in a 

 straightforward way approached me directly in such matters, 

 and it is no excuse for his dubious course of action to say 

 he had an " introduction." My assistant has explained his 

 position in the matter in letters addressed to '■'^Engineering" 

 within the last few weeks. The paper of 1895, on gas jets con- 

 taining liquid, has been a fruitful source of recrimination. No 

 less than three patentees of low temperature apparatus — viz. 

 .Solvay, Linde and Hampson — have each recognised in its con- 

 tents part of the essential subject-matter of their respective 

 patents. It will be for these gentlemen to fight the matter out. 

 Suffice it to say, that the statements made in my paper of 1895 

 remain a correct record of facts. Further remarks on the subject 

 can be found in the Society of \x\s, Journal for March 1898 ; 

 made during the course of a discussion on the Linde process. 



The Hampson patent was not published before April 1896, 

 and the first exhibition of the working apparatus took place to- 

 wards the end of March of the same year ; or some three months 

 subsequent to my Chemical Society paper. Mr. Hampson 

 declares in his letter that he '■'' was afterwards the first in this 

 country to liquefy air atid oxygen without employing other re- 

 friaerants." Now, in my paper of 1895 the following passages 

 occur : — "With such a simple apparatus and an air supply at 200 

 atmospheres, with no prez'ious cooling, liquid air begins to collect 

 in about five minutes, but the liquid jet can be seen in between 

 two and three minutes." " In the above experiments air is 

 taken at the ordinary temperature, which is a little above twice 

 its critical temperature, and is partially transformed in a period 

 of time, which in my experiments has never exceeded ten 

 minutes, simply and expeditiously into the liquid state at its 

 boiling-point — 194", or a fall of more than 200° has been 

 effected in this short period of time." J. Dewar. 



May 30. 



Printed Matter and Photographic Plates. 



In connection with this subject it does not appear to be 

 generally known that photographic negatives, after they have 

 been developed and fixed, and especially if they have been in- 

 tensified by means of the bi-chloride of mercury and ammonia 

 process, are often strongly impressed by prolonged contact with 

 printed matter. I first observed this many years ago, and have 

 a large number of negatives in my possession which show the 

 effect very strongly, I enclose a photographic negative taken 

 by myself in 1882, which has remained since 1886 wrapped up 

 in the accompanying advertisement sheet of the Electrician. 

 As will be observed, the greater portion of the print in contact 

 with the film is clearly legible. It is, however, worthy of note 

 that it does not appear to be the printer's ink in this case that 

 has produced the chemical action, but rather the paper itself, 

 or some ingredient therein. Those portions of the film pro- 

 tected from contact with the paper by the ink have retamed 

 their original colour, while the other portions not so protected 



NO. 1493, VOL. 58] 



have become very considerably bleached. The printing on the 

 side of the paper removed from the film does not seem to have 

 had any effect. 



It has probably been noticed by others that ordinary albu- 

 menised and sensitised photographic paper is also strongly 

 affected in the course of time by contact with printed matter. 

 In this case, also, the printing comes out as white lettering upon 

 a darker ground. A. A. C. Swinton. 



The Transport of Live Fish. 



Your readers may be interested to know of an experiment 

 with the transport of live fish I am making, and so far success- 

 fully. I left Brisbane on April 16, taking with me four speci- 

 mens of Ceratodus. This remarkable fish is doubtless sufficiently 

 well known to your subscribers to render a description on my 

 part unnecessary. D. O'Connor. 



S.S. Duke of Devonshire, Colombo, May 16. 



CEREMONIAL DANCES OF THE AMERICAN 

 INDIANS. 



READERS of Nature do not need to be reminded 

 of the important work being done by the Bureau 

 of American Ethnology, which is conducted under Act 

 of Congress " for continuing ethnologic researches among 

 the American Indians under the direction of the Smith- 

 sonian Institution." The value of the researches that 

 are being carried on, and the results of which are issued 

 in the form of annual reports and bulletins, cannot be 

 over-estimated ; for the Indian customs and beliefs, which 

 form the subject of the majority of the papers, are not 

 destined to survive for many years. The Indian reserves 

 are gradually being curtailed, the Indians themselves 

 are slowly becoming civilised, and this process is naturally 

 attended with change and decay of their primitive 

 ceremonial and belief. It must be admitted that the 

 Indian nature is slow to change, and retains its tribal 

 instincts under a veneer of civilisation. In fact, the case 

 of a young Arapaho Indian, who, though speaking good 

 English and employed as a clerk in a store, thought it 

 but natural that he should join his tribe in dancing the 

 sun-dance for three days and nights without food, drink 

 or sleep, is far from exceptional. But the change, though 

 gradual, is constant, and at no distant period the American 

 Indian will have ceased to furnish the anthropologist 

 with opportunities for the study of primitive man. When 

 that time arrives the value of these reports, compiled by 

 trained observers in accordance with a scientifically 

 organised plan, will be unique. 



The present article is concerned with three of the 

 papers published in the fourteenth, fifteenth and six- 

 teenth annual reports of the Bureau. These papers may 

 be classed and considered together, as they deal with 

 certain ceremonial dances still practised by many of the 

 Indian tribes. The longest of the papers is that entitled 

 "The Ghost-dance Religion and the Sioux Outbreak of 

 1890," which is contributed by Mr. James Mooney, and 

 is published in a volume by itself as Part ii. of the 

 fourteenth annual report. The underiying principle 

 of the ghost-dance is the doctrine that at some future 

 time the whole Indian race, whether living or dead, will 

 be reunited in a life upon earth untroubled by the fear of 

 death, hunger, or disease. Most Indians hold that this 

 change will be brought about by spiritual powers who 

 will require no assistance from men, but at times of dis- 

 content medicine-men have sought to anticipate the 

 Indian millennium by preaching a crusade against the 

 further encroachments of the white population, and per- 

 suading their fellow tribesmen that m this resistance 

 they will have the active support of their dead ancestors 

 and relatives. Such a revival took place in 1890 among 

 the Sioux, the largest and strongest Indian tribe in the 

 United States. The cause of the outbreak may be traced 

 to irritation at the encroachments made on their reserve 



