404 



NATURE 



\_Augtist 23, 1888 



While the rigid investigation of facts is no doubt one of the great 

 methods of science, we must not forget that by asking questions as 

 to the use or value of a particular physiological arrangement, we 

 may obtain light as to the road along which investigations are 

 to be pursued. This is the guiding star of Fleischl von Marxow's 

 speculation, and it has led him and other physiologists to 

 scrutinize anew the theories of respiration now in vogue. 



In this address we have had abundant evidence of the fact that 

 physiology, in the solution of some of her problems, depends en- 

 tirely upon the methods of chemistry and physics. The air-pump, 

 the special advantages of the mercurial air-pump, the methods 

 devised for collecting and analyzing the gases of the blood, the 

 spectroscope, have all contributed important facts to our know- 

 ledge of respiration. The narrative placed before you also illus- 

 trates in a striking manner the relation of modern physiology to 

 the physiology of our forefathers. The latter were engaged in 

 observing and explaining the more obvious phenomena, whilst 

 the modern physiologists are pushing their researches further, and 

 are endeavouring to study the hidden phenomena, which, like a 

 second order, lie behind these. I need scarcely add that even the 

 results of modern research are not to be regarded as final. 

 Although we see a little further and more clearly than those who 

 went before, there is still uncertainty as to fact and obscurity as 

 to explanation in most departments of physiological science, and 

 not least as regards the function of respiration. Enough has 

 been said to show that in the study of respiratory mechanisms we 

 meet with numerous examples of the same wonderful adaptation 

 of organic structure to physical conditions as may be traced in 

 the mechanism of the eye and of the ear. The structure of a 

 lung or of a gill is just as much adapted for the play of the 

 physical laws regulating gases as the retina is tuned to the 

 vibrations of the ether, or as the organ of Corti responds 

 sympathetically to the waves of musical tone. 



List of Experiments in illustration of the Lecture. 



1. Appearance of blood after having been shaken with carbonic 

 acid. 



2. Appearance of blood after having been shaken with 

 hydrogen . 



3. Appearance of blood after having been shaken with 

 nitrogen. 



4. Appearance of blood after having been shaken with oxygen. 



5. Fac-siniile model of Leeuwenhoek's syringe, by which gases 

 were first demonstrated in the blood. 



6. Absorption of ammonia by water. 



7. Gases escaping from water in Torricellian vacuum. 



8. Gases escaping from blood in Torricellian vacuum. 



9. Spectrum of oxyhemoglobin shown by electric light. 



10. Spectrum of reduced haemoglobin ; the reduction effected 

 by ammonium sulphide. 



1 1. Spectrum of oxyhaemoglobin changing into that of reduced 

 haemoglobin by heating blood in vacuo. 



12. Demonstration of a new gas-pump for the physiological 

 lecture table (Figs. 1, 2, and 3). 



13. Demonstration of the use of Pfliiger's gas-pump. 



14. Collection of blood-gases and demonstration of the 

 existence of carbonic acid and of oxygen. 



15. Carbonic acid collected from a solution of carbonate of 

 soda in vacuo. 



16. Method, by use of thermo-electric piles with galvano- 

 meter, of observing thermal changes attending formation of 

 oxyhemoglobin. 



17. Demonstration of Fleischl von Marxow's experiment?, not 

 with a syringe, but with the fluid in a Torricellian vacuum so 

 arranged as to receive a shock. 



Dr. McKendrick asks us to direct the attention of our readers 

 to a statement in his address which he wishes to correct. He 

 stated : " If the union of oxygen with the colouring matter is an 

 example of oxidation, it must be attended with the evolution of 

 heat, but, so far as I know, this has not been measured." He 

 then referred to a method by which Mr. J. T. Bottomley and he 

 had been able to observe the heat produced. Dr. McKendrick 

 was not then aware of an important research on this subject 

 conducted in 187 1 by his friend Dr. Arthur Gamgee, and con- 

 tained in a Report to the British Association for the Advance- 

 ment of Science in 1871. Dr. Gamgee, both by the use of 

 thermometers and by thermo-electric arrangements, demonstrated 

 the important fact that an evolution of heat accompanies the 

 union of oxygen with haemoglobin, and in the Report referred to 

 there is ample evident that the research was conducted with 



great skill and with an appreciation of the difficulties to be 

 surmounted. He arrived at the conclusion " that the mean rise 

 of temperature during the absorption of oxygen amounted to 

 o°'0976 C. The maximum heating found was o°iu C, and 

 the minimum o c- o83 C." 



MOLECULAR PHYSICS: AN ATTEMPT AT A 

 COMPREHENSIVE DYNAMICAL TREAT- 

 MENT OF PHYSICAL AND CHEMICAL 

 FORCES. 1 



I. 



'"FHE author states that his attention was drawn to the 

 subject in the first place by personal intercourse with 

 Sir William Thomson, and by his opening address to the Mathe- 

 matical and Physical Section of the British Association at the 

 Montreal meeting in 1884, followed by the study of the litho- 

 graphed report of his lectures on " Molecular Dynamics" at the 

 Johns Hopkins University. 



The opening paragraph of the paper contains a restatement of 

 the portions of Thomson's theory applicable to the explanation 

 of optical phenomena. Thomson did not succeed in arriving at 

 a satisfactory explanation of the fact that metallic reflection and 

 double refraction are accompanied by little or no dispersion. 

 The author believes that he has overcome this difficulty by a 

 more complete discussion of the formulae by expansion in series. 

 He then proceeds to apply the theory to the explanation of 

 chemical phenomena on a purely dynamical basis, and arrives 

 at a method of determining the spectrum of a compound from 

 the spectra of its constituents. 



The second portion of the paper is quite independent of the 

 first, and also of Thomson's theories, except that it gives a com- 

 plete explanation of the manner in which the ether vibrations 

 can be taken up by the molecules of a body. 



The author endeavours to explain electrical phenomena by 

 transverse vibrations of the ether, which are very small com- 

 pared to the diameter of a molecule or of an atom, and one of 

 the most remarkable and interesting results of his investigation 

 is that the theory leads to Weber's law expressing the mutual 

 action of two electric currents, subject to a restriction which 

 excludes exactly those cases the consideration of which led 

 Helmholtz to the conclusion that the law was untenable. A 

 further confirmation of the theory is given by its explanation of 

 a number of other phenomena, such as fluorescence, magnetism, 

 and diamagnetism, and the electro-magnetic rotation of the 

 plane of polarization. 



Part I. — Light, Heat, and Chemical Affinity. 

 § 1. — T/ze Internal Structure of Molecules. - 



The ether is assumed to fill the whole of space, and to be 

 everywhere of equal elasticity and density. It is further assumed 

 that, with respect to vibrations of periods comparable with those 

 of light-waves, the ether behaves like a perfectly elastic solid ; 

 while with respect to slower vibrations, such as those due to the 

 motion of gaseous molecules, it behaves like a perfect fluid, so 

 that the molecules can traverse it freely. 



A molecule is supposed, on Thomson's 3 theory, to consist of 

 a solid core inclosed within a series of spherical shells. Between 

 the core and the innermost shell there is supposed to be an 

 elastic action of a nature which might be represented by a series 

 of symmetrically disposed elastic springs. 



A similar elastic action is supposed to take place between 

 every pair of adjacent shells, and also between the outermost 

 shell and the external ether. 



Let j be the number of shells in a molecule, and let their 

 masses, beginning with the outermost one, be 



Mi M_a M; 



47T- 4TT- 47T" 



The centres of the core and shells may be supposed to lie in a 

 straight line and to be capable of oscillations along this line. 

 The elastic force between each pair of shells is assumed to be pro- 

 portional to the relative displacement of their centres ; and that 

 between the outermost shell and the external ether, proportional 



1 A Paper read before the Physico-Economic Society of Konigsberg, by 

 Prof. F. Lindemann, on April 5, 1888. 



2 The author generally uses the term molecule to denote either an atom 

 or a molecule except when he is considerirg chemical compounds. — G. W. T. 



3 " Lectures on Molecular Dynamics and the Wave Theory of Light," by 

 Sir William Thomson. (Baltimore, 1884.) 



