48o 



NA TURE 



{March 17, 1887 



Physiological Society, February ii. — Prof, du Bois-Rey- 

 mond in the chair. — Dr. Konig spoke on acuteness of hearing and 

 its estimation by means of tuning-forks, the sound of which gradu- 

 ally died away. He laid stress on the distinction between acute- 

 ness of seeing and acuteness of hearing, the latter of which was 

 represented by the time from the beginning of hearing a tuning- 

 fork struck till no sound from it was any longer perceived. 

 It was now customary to say when one person could hear a 

 certain tuning-fork for loo seconds after it had been struck, and 

 another could hear the s.ame tuning-fork, struck at the same 

 intensity, for only 50 seconds, that the second had only half the 

 acuteness of hearing possessed by the first. In point of fact, 

 such a statement was not accurate, seeing that the amplitudes of 

 a vibrating tuning-fork declined in geometrical progression. It 

 was only in very special circumstances that the S|3ecification of 

 the amount of acuteness of hearing, as commonly employed, 

 could be correct. As an empirical method of measurement 

 according to a conventional standard, the expressions a half, a 

 quarter, or whatever be the measure, of acuteness of hearing 

 would be permissible, if in such cases the same timing-fork were 

 always applied, and it was always struck with the same intensity. 

 To come to an understanding on this point was the business of 

 practical aurists. During the animated discussion which followed 

 this address. Prof, du Bois-Reymond produced an apparatus in 

 which an equal amplitude of vibration in a tuning-fork was 

 obtained by placing between the prongs of the fork a revolving 

 elliptical disk of such dimensions that the small axis left the 

 prongs in their natural position, while the large axis forced them 

 apart from one another. The large axis having been put in, 

 and the disk rapidly turned through 90°, the fork commenced 

 to vibrate, and with each impulse the amplitude was the same. — 

 Prof. Zuntz reported the results of the experiments, partly in- 

 stituted in conjunction with Herr Potthast, respecting the ali- 

 mentary values of various albuminous substances. As a most 

 important principle in conducting these experiments, the speaker 

 laid down the maxim that the albuminous substance to be 

 examined should not be administered in too large quantities. 

 It was only with very small doses that the alimentary value of 

 the different albuminous substances beside the same nourish- 

 ment free of nitrogen could be determined. The dog was used 

 for the purpose of the experiment. The proteine substances 

 compared were : the albumen of lentils, that of lupines, that of 

 gluten, and caseine. In the normal feeding, which regularly 

 alternated with that of the albumen to be tested, the proteine of 

 nourishment was imparted in the form of flesh-meal. The result 

 of the long and laborious experiments was that the alimentary 

 value of the albumen of lentils and that of gluten were each 

 found to be equivalent to that of flesh-meal. That is to say, 

 when to the food (which, apart from the additions to be specified, 

 was the same in all the different cases) there were added equal 

 quantities of albuminous nitrogen — in one case in the form of 

 flesh-meal, in another in the form of gluten, and in a third in 

 the form of lentils — in each such case a quantity of nitrogen was 

 developed, and therefore a quantity of albumen withdrawn from 

 the nourishment, which was equal in all three. The albumen 

 of lupines had a lower alimentary value than the albumen of 

 flesh-meal, seeing that from the lupines more albumen was 

 decomposed than from the flesh-meal. Finally, from caseine, 

 less albumen was decomposed, and therefore more was absorbed 

 by the body and utilised, than in the case of any of the other 

 albuminous classes. By means of this investigation two facts of 

 general importance were established : first, it was ascertained 

 that by changing the species of albumen employed by way of 

 nourishment, a better utilisation of the nutritive albumen 

 was obtained, i.e. less albumen was decomposed, than if one and 

 the same species of albumen were given for a long period ; 

 second, the paradoxical observation was made that during lacta- 

 tion, when the animal made use of a large quantity of albumen 

 for the formation of milk, more of the albumen administered in 

 the food passed away in waste than would have been the case in 

 the same circumstances at a time of non-lactation. The follow- 

 ing explanation of these phenomena was given by the speaker. 

 During lactation the animal used a certain quantity of albumen 

 for the milk. The albumen of milk, as was known, was caseine. 

 This caseine was not, however, administered in the food, but 

 had first to be produced from the nutritive albumen (the various 

 species of albumen being chemically different. Now, from the 

 nutritive albumen only certain groups of molecules could be utilised 

 for the formation of caseine. Far more albumen must therefore be 



decomposed than corresponded with the quantity of nitrogen in 

 the caseine. Hence, therefore, the greater decomposition and the 

 less utilisation of the albumen of the nourishment. Nor was the 

 albumen which the animal needed for incorporation with the 

 body offered to it in the albumen of the nourishment, but the 

 albumen taken by the body was built up from the constituents of 

 the albumen of the nourishment. If only one kind of albumen 

 was given to the animal, it required to decompose a large quan- 

 tity in order to obtain sufficient constituents for the albumen 

 appropriated by the body. If, on the other hand, different sorts 

 of albumen were given in the food, then the animal decom- 

 posed on the whole a less percentage, seeing that in the differ 

 ently composed albuminous substances it sooner found the 

 different molecular groups which it needed for the building-up 

 of the albumen of the body. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED 



Records of the Geologic.il Society of Indi.i, vol. xx.— The ABC of 

 Photography, 22nd edition (London Stereoscopic Company). — The Perfect 

 W.iy, or the Finding of Christ, 2nd edition: Kingsford and Maitland 

 (Field and Tuer).— English Tobacco Culture: E. T. Beale (Marlborough). 

 — Through the Fields with Linnseus, 2 vols. : F. Caddy (Longmans). — 

 Report of the Meteorological Council of the Royal Society for the year 

 ending March 31. 1886 (Eyre and Spottiswoode). — Quarterly Weather 

 Report, part 2. April-June, 187B (Eyre and Spottiswoode).— Monthly 

 Weather Report, September 18S6 (Eyre and Spottiswoode). — Report 

 of the Third fleeting of the International Meteorological Committee, held 

 at Paris, September 1885 (Eyre and Spottiswoode).— Scalelia Chemica : a 

 Series of Aids for Beginners in Chemistry ; Part i. Analysis of Simple Salts ; 

 H. Adrian (Lewis).— Genesis of the Elements : W. Crookes.— The House in 

 Relation to Public Health : J. B. Russell (Anderson, Glasgow).— Descrip- 

 tive List of Anthropometric Apparatus (Cambridge Scientific Instrument 

 Company). — Annalen der Physik und Chemie, No. 3, 1867 (Earth, Leipzig). 

 — Journal of Physiology, vol. viii. No. 1 (Cambridge). 



CONTENTS 



PAGE 



The State and Higher Education 457 



Practical Zoology 458 



The Dutch Colonies in South America and the 



West Indies. By Dr. A. Ernst 459 



Hydraulic Power and Hydraulic Machinery. By 



Major Allan Cunningham, R. E 460 



Our Book Shelf:— 



" The Statesman's Year-Book for 1887" 461 



"Joint Scientific Papers of James Prescott Joule, 



F.R.S." " 46' 



Letters to the Editor : — 



The Earthquake. — W. H. M. Christie, Astronomer- 

 Royal. (Illustrated) 462 



The Engineer on the Dimensions of Physical 



Quantities.— P. G. T 462 



Tabasheer. — Tokutaro Ito 462 



"The Origin of Mountain Ranges." — T. Mellard 



Reade ; Prof. A. H. Green, F.R.S 463 



The Vitality of Seeds.— F. G. Hilton Price ; L. 



Blomefield ; Dr. L. Martial Klein 463 



Cerebral Localisation, II. By Prof. E. A. Schiifer, 



F.R.S 464 



The Value of the New Apochromatic Lenses . . 467 



Atlantic Weather Charts 469 



Gilded Chrysalides. By Edward B. Poulton . . . 470 



Notes 471 



Our Astronomical Column : — 



Telegraphic Determination of Australian Longitudes 474 



Comets and Asteroids 474 



The Tails of the Comets of l886 474 



Minor Planet No. 265 474 



Astronomical Phenomena for the Week 1887 



March 20-26 474 



Geographical Notes 475 



Prehistoric Remains in America. (Illustrated) . . 476 



University and Educational Intelligence 477 



Scientific Serials 477 



Societies and Academies 477 



Books and Pamphlets Received 4S0 



