246 



NATURE 



[July 14, 1898 



contraction occurred, and the spectrum of the gas was unahered, 

 after removing oxygen. 



(3) An artificially made mixture of carbon monoxide and argon 

 — about equal volumes of each — was mixed with oxygen. It 

 was sparked and exploded. It was then further sparked over 

 soda for a quarter of an hour. On introducing the gas into a 

 vacuum tube, after removal of oxygen, no carbon lines or bands 

 were seen, but only the spectrum of pure argon. 



The bands in the green of metargon are exceedingly brilliant, 

 and the spectrum is by no means of the character of a subsidiary 

 one. It does not appear to be possible to enfeeble them 

 relatively to the rest of the spectrum. 



We have found it possible, in hundreds of cases where it was 

 necessary, to remove traces of carbon compounds from gases 

 evolved in heating minerals — chiefly helium — to remove the 

 carbon bands by "running" the tube, i.e. by increasing the 

 intensity of the current until the aluminium pole melted. The 

 green and red bands, under these circumstances, slowly disappear, 

 and the spectrum of helium or of argon, as the case may be, 

 shines out " clean-cut," and shows as bright lines on a black 

 background. This process is impossible with metargon ; no 

 change is produced even after long " running." 



We must again call attention to the facts that this gas shows 

 the ratio of specific heats i "66 ; that it possesses sensibly the 

 same density as argon ; and that it is a solid at the temperature 

 of liquid air, boiling under atmospheric pressure. 



Although, therefore, we are the first to admit that the spectrum 

 of this gas requires further investigation, yet, from what we have 

 observed, we provisionally adhere to our original view that it 

 possesses the characteristics of a definite chemical individual. 



We would take this opportunity of correcting a misprint in 

 the Comptes rendiis, cxxvi. p. 1762, where the wave-length 

 5849*6 is attributed to metargon, instead of to neon. 

 W, Ramsay. 

 M. W. Travers, 

 Edward C. Cyril Baly. 



University College, London, Gower Street, W.C. 



Liquid Hydrogen, 



Prof. Dewar's letter in your last issue is such a pronounced 

 personal attack on me, that I feel I ought to deal with the 

 remarks to my prejudice which it contains, though I will try to 

 avoid imitating its tone. 



(i) He refers to the statements on which I base my claim to 

 the invention of the self-intensive method as matter which " has 

 already been refuted." I should be glad to know when and by 

 whom. They are clearly numbered i, 2, 3, 4, in my last letter, 

 and form the substance of my first. At the Society of Chemical 

 Industry Mr. Lennox, though he was present and heard the 

 statements repeated, with every opportunity of contradicting 

 them, did not do so. Prof. Dewar, far from refuting statements 

 I and 3, did not even deny them ; and his attack on the second 

 (respecting the novelty of the invention) resulted in strengthening 

 it, since it showed that he was reduced to building up an antici- 

 pation by taking material from several different sources, having 

 tjeen unable to find any account of the combination before my 

 proposal in November 1894. The fourth statement had not 

 then been made, as hydrogen had not been liquefied. Where 

 then has the refutation taken place ? In both his letters to you 

 Prof. Dewar keeps all four statements at a very respectful 

 distance. 



(2) Prof. Dewar uses the words " accusations which he was 

 compelled to withdraw when he met me face to face," and 

 " when brought to book at the Society of Chemical Industry." 

 It is quite untrue that I withdrew anything at all. On the con- 

 trary, I said that " I had nothing to withdraw," and that my 

 assertions were "a simple and direct statement of historical 

 facts," repeating more frequently than is shown in the printed 

 report that the facts were exactly as I had stated them. As to 

 what took place between Prof. Dewar and his assistant it is 

 obvious that, not having been present, I could have no know- 

 ledge ; and I can only publish what I know of my own know- 

 ledge, or can prove by conclusive evidence. Deductions from 

 the facts must be made by every one for himself, and I reminded 

 Prof. Dewar that as I had published no such deductions I could 

 not withdraw them. 



(3) I was not, at the time of my communications to Mr. 

 Lennox, "convinced of the general dishonesty of Royal 

 Institution methods," as Prof. Dewar suggests. I regarded the 



NO. 1498, VOL. 58] 



Royal Institution as one of the temples of science, and Mr- 

 Lennox as its chief acolyte, who might, perhaps, when my 

 offering had been examined and found worthy of acceptance, 

 introduce me to the favourable notice of higher authorities. 



{4) What I am " to be understood as saying in the letters youi 

 have published," is so clearly set forth in my four numbered 

 statements in your issue of June 23, that Prof. Dewar's doubts 

 on the point cannot be so puzzling as his question implies. 



(5) Prof. Dewar's acquaintance with patent-law cases in- 

 volving a host of partisan expert witnesses and costly counsel is- 

 too extensive and familiar to leave him in any doubt as to the 

 reason why a man without means does not begin a prosecution, 

 for infringement. I could, however, warn the infringers ; and 

 this I did. The protest having been made, I am still free to- 

 prosecute when circumstances render it possible and advisable 

 to do so, and the present prospects of low-temperature work 

 make it by no means unlikely that action may yet be taken. 



(6) Prof. Dewar's admission, referring to Dr. Linde's method,, 

 which he had just heard described, "that the practicability of 

 such a mode of working had never struck him," was made in 

 the opening sentences of his remarks, without any limiting 

 qualifications, but with express inclusion of both "the 

 mechanical ingenuity and knowledge of thermodynamics " in- 

 volved ; so that its only fair interpretation is with reference to- 

 the description that had just been given of Dr. Linde's combin- 

 ation, which is, except in details, the same as mine. The force 

 of the admission is not lessened by quoting a subsequent passage 

 which refers to one part of the combination. Dr. Linde and I 

 had invented a combination which made it possible to liquefy 

 air without using any other refrigerant than water. Prof. Dewar 

 admitted that he had never thought out the whole combination. 

 Whatever therefore he and others had done with some parts of 

 it, when the combination came out he ought to have recognised 

 its novelty, instead of endeavouring to piece it together out of 

 old patents and experiments. 



(7) Neither M, Solvay nor Prof. Onnes claims to have 

 invented a combination by which continuous free expansion- 

 from a nozzle is able, without using other refrigerants, to liquefy 

 air : so that Prof. Dewar misleads his less instructed readers by 

 putting those gentlemen forward as my rivals on the ground that 

 they claim to have used parts of the combination. 



My communications to Prof. Dewar's assistant were, however, 

 of earlier date than any publication of Dr. Linde's process. 

 This is the fact of which, with its corollaries, I had hoped to 

 obtain a frank admission from Prof. Dewar, and I would have 

 much preferred that the discussion in your columns had been 

 confined to the points raised in my first letter. Prof. Dewar, 

 however, instead of frankly admitting my claims, as other 

 prominent scientific men have done, or discussing the statements 

 on which they are based, has seen fit to give his attention almost 

 entirely to the more personal elements in the controversy. In- 

 two letters he has called my action "dubious" and "not straight- 

 forward," and has said that either I am " a singularly dull person " 

 or am consciously imposing "upon the credulity of the world," 

 that I contradicted myself " when brought to book," and that I 

 "was compelled to withdraw accusations" which in fact I 

 explained that I had never made, while refusing to withdraw 

 anything at all. Under these circumstances I think that few of 

 your readers will blame me for asserting the justice of my claims, 

 though I regret that so much of your valuable space should have- 

 been occupied by matters of this nature. W. Hampson, 



July I. 



The Distribution of Prepotency, 



No numerical estimate appears to have been made of the 

 frequency with which different grades of prepotency are dis- 

 tributed. Breeders are familiar with the fact that certain 

 animals are peculiarly apt to impress their personal characters 

 upon offspring, but how frequently and to what extent this 

 tendency occurs has never, I believe, been investigated. The 

 following attempt is therefore of interest, though not free from 

 objection in minor details. In Wallace's Year Books of the 

 American Trotting Horses, lists are given (i) of the sires of 

 offspring, any one of which has succeeded in trotting one mile 

 in 2 minutes and 30 seconds or less, or who has "paced" 

 (= ambled) the same distance in 2 minutes and 25 seconds or 

 less ; (2) of the dams of at least two such offspring, or else of 

 one such offspring and one such grandchild. A selection was- 

 made from lists (i) and (2) of sires and dams who were them- 



