December 13. 1891] 



NATURE 



167 



and the right to a table in iSgi.was secured to Americans, 

 only through the private benefaction of Major Alex. Henry 

 Davis, of Syracu5e. For the year 1892 the use of a table has 

 been secured through a subscription started by the American 

 Association for the Advancement of S:ience, toward which the 

 Association itself granted out of its scany funds loo dols. and 

 was the means, I believe, of procuring the rest.' 



We have not, however, been wholly without some such means 

 of study in this country through the marine biological 

 laboratories established some years ago at Newport and at 

 Wood's Holl, by Prof. Alex. Agassiz. The former has been 

 now enlarged so as to accommodate eight advanced students, 

 besides the professor and his assistant." The Johns Hopkins 

 University also has supplied some opportunities of this kind by 

 its summer school, formerly at Beaufort ; later, at Jamaica ; 

 but at present, as I understand, it is without any permanent 

 location. 



Our neighbour, the Brooklyn Institute, has organised similar 

 investigations, on a minor scale, during the summer months at 

 different places on Long Island. But what is needed for the 

 most effective work is suitable endowments for professors and 

 advanced students, in connection with an adequate biological 

 laboratory, such as the Newport one enlarged might afford, 

 equal in means and equipment to that at Naples, or at least to 

 that recently completed, largely through private enterprise, at 

 Plymouth, England.' 



{To be continued.) 



SCIENTIFIC SERIALS. 



Bulletin de f Acadimie Royale dc Belgii]iie, Nos. 9 and 10. — 

 On the conversion of black mercuric sulphide into red sulphide, 

 and OR the density and specific heat of these bodies, by W. 

 Spring. As a general rule, if a body is capable of existing in 

 two allotropic states with different densities, it is possible to 

 convert the lig hter into the heavier kind by compressing it to the 

 higher density, the pressure depending upon its compressibility. 

 Sometimes this conversion is only possible above a certain 

 "critical temperature." In the case of the sulphide of mercury 

 the conversion of the black into the red variety (vermilion) 

 involves a compression of 9 per cent., and would require a 

 pressure of 35.000 atmospheres, which is not at present attain- 

 able. But M. Spring has succeeded in obtaining a new form of 

 black HgS which only requires 2503 atmospheres. It is 

 obtained by sublimation of ordinary black HgS in an .Ttmo- 

 sphere of nitrogen or C0„. Its density is 80395, while that of 

 vermilion is 8 1587, and of ordinary black HgS 7'6242. A 

 curious side result of the investigation is that the black sulphide 

 hitherto known, after being made to expand by heat and then 

 cooled, takes al>out a day to return to its original density. — 

 Vapour tension and hygrometric state, by Dr. J. Verschaffelt. 

 A new hygrometer may be based upon the fact that the hygro- 

 metric state of the atmosphere may be taken as the ratio of the 

 vapour tension inside a solution to the highest possible vapour 

 tension of water at the same temperature, if the tension inside 

 the solution is equal to that in the atmosphere, i.e. when the 

 solution does not evaporate or gather moisture from the air. 

 The ratio mentioned is independent of the temperature, and 

 hence the humidity is simply a function of the concentration of 

 the solution. In practice. Dr. Verschaffelt moistens a weighed 

 piece of blotting-paper with a weighed quantity of a solution of 

 lithium chloride of known concentration, exposes it to the 

 atmosjihere, and weighs it again. From the last weight the 

 "equilibrium concentration " may be calculated, and from this 

 the humidity with the aid of Dieterici's data for this salt. The 

 apparatus might be made self-registering. 



t See l^ro^ccdittf^s .■liiurican Association .-/. .S". 1891, vol. .\I. p. 449-451. 



- Ke/iort ilan'ard Colieee, 1891, p. 182. 



3 In his address before the American Association for the Advancement 

 of Science, in 1891, President Prcscott, referring to this general subject, said: 



" To nurture investigation in science is the Kirgcst opportunity before the 

 American people. Research, systematic and wisely directed, requires good 

 organisation and strong support, the supporc of many powers. It must have 

 the support of able and persistent men. It needs the conference of workers, 

 and the dissemination of knowledge in societies like this. It wants the 

 interest .-.nd the confi^lence of the public. Itasks and will alwaysobtain the 

 constant, helpful use of the press. It retiuires distinct provision in cjlleges, 

 and in the institutions of higher education. It ought to be sustained 

 expressly by the Government, both in the several States and under the 

 United States, and sustained on broad and permanent foundations. Still, it 

 needs private benef.actions. Research is the growth of years. Let it be 

 the demand of all, and let this call find utterance' everywhere.** — I'rocccd- 

 ingt Atuctuan .■Issociaiion, 1891, vol. .\I. p. 440. 



Bulletin of the American Afniliematical Society, vo]. i. No. 2. 

 (New York, iMacmillan, November, 1894.) — On the problem 

 of the minimum sum of the distances of a point from given 

 points, is the translation, by A. Ziwet, of a paper presented to 

 the Society at its summer meeting J.Vugust 15), by Prof. V. 

 Schlcgel (pp. 33-52). This frequently discussed problem (see 

 references given by Slurm, Cretle 5 Journal, vol. 97), is con- 

 sidered by the author to offer room for further treatment. He 

 discusses the best method of investigating the question, and in 

 the end treats it by means of the simplest methods of Grass- 

 mann's " .\usdehnungslehre." Prof. Cajori collects a number 

 of authorities in confirmation of a statement in his " History 

 of Mathematics" (p. 218), that it is not true that the binomial 

 theorem is engraved on Newton*s monument in Westminster 

 Abbey. The latest additional authoriiy for his statement is 

 contained in a letter from the present Dean of Westminster, 

 whom Prof. Cajori calls "Dr. Granville" I— The only other 

 matters are the notes and new publications. 



NO. 1311, VOL. 51] 



SOCIETIES AND ACADEMIES. 



Cambridge. 



Philosophical Society, November 26. — Prof. J. J. 

 Thomson, President, in the chair. — (Jn Benham's artilicial 

 spectrum, by Prof. G. D. Liveing. Prof. Liveing exhibited 

 one of Benham's "artificial spectrum tops" (see Nature, 

 November 29, p. 113), and a variety of discs with figures in 

 black disposed on a white ground, and with white figures on a 

 black ground, which, when revolved in a bright light showed 

 remarkable bands of colour of various shades of red, green, and 

 blue. The general result of his observations of these discs was 

 that if a succession of black and while objects were presented 

 to the eye with moderate, but not too great, rapidity, then, 

 when black was followed by white, an impression of a more or 

 less red colour was perceived, while when white was 

 succeeded by black a more or less blue colour was 

 perceived. If the succession of black and white was 

 very rapid the appeaiance presented to the eye was 

 of a more or less neutral green or drab. The explanation 

 offered by Prof. Liveing was based on the known facts that the 

 impression produced on the retina by a bright object remained 

 for an appreciable time after the light from the object had been 

 cut off, and that the duration of that impression was different 

 for different colours ; and on a supposition, which he did not 

 know to have been as yet verified experimentally, that the 

 rapidity with which the eye perceives colours was greater for 

 one end of the spectrum than for the other. From this point of 

 view the explanation of the blue colour seen when white is 

 followed by black would be that the impression of blue on the 

 retina lasts a little longer than that of the other colours ; while 

 the red colour seen when while succeeds black is due to the 

 greater rapidity with which the eye perceives red light than that 

 with which it perceives blue. If, however, the alternations of 

 white and black succeed each other with sufficient rapidity, the 

 new impression of a white patch will be produced before that of 

 its predecessor has vanished, and there will be an overlapping 

 of impressions, and the sensation will be that of a mixture of 

 colours, or of a more or less neutral tint. So far as he could 

 test the theory by his osvn eyes it appeared to him that the 

 residual impression, left when the light from a white object was 

 suddenly cut off, was at first green and faded out through a 

 more or less blue or slate colour. — On a simple test case of 

 Maxwell's law of partition of energy, by Mr. G. 11. Bryan. 



Paris. 



Academy of Sciences, December 3. — M. Lnewy in the 

 chair. — The reduction of alumina by carbon, by JI. Henri 

 Moissan. The author describes the reduction of pure corundum 

 by means of his now well-known electric furn.ice. Liquid 

 alumina is not reduced by carbon ; the reduction only takes 

 place when the vapours of these substances are carried to a very 

 high temperature, metallic aluminiuin is then produced and 

 partially combines with carbon. — Reply to M. Mayer-.Vymar 

 concerning his defence of .Sa/uiricn as a name for the latest 

 geological period, by M. A. Pomel.- — \ letter from Prof. K. 

 Fresenius was read announcing the formation of a German 

 committee in connection with the Lavoisier monument. The 

 Academy appointed Prof. Fresenius delegate for this work. 

 Prof. G. Hinrichs was similarly appointed delegate for the 



