September 4, 1919J 



NATURE 



»5 



lOfOoo individual measurements. He has recently dis- 

 sected some fifty stools, representing twenty-four varie- 

 ties, and finds overwhelming evidence that the late 

 canes are the thickest, thus reversing earlier con- 

 clusions drawn from the behaviour of the Punjab 

 canes late in the season. 



GENERAL PHYSIOLOGY. 



INCREASED specialisation brings with it further 

 ■^ subdivision of the sciences, and most of the new- 

 journals which are founded are restricted to narrower 

 fields than those of existing publications. Now and 

 then, however, an attempt is made to counteract the 

 evils of specialisation by msistence on broad principles 

 and by the provision of a meeting-place for workers 

 in various branches of the same or of kindred sub- 

 jects. Some such considerations must have led to the 

 recent foundation of the Journal of General Physiology, 

 which is edited by Prof. Jacques Loeb, a physiologist, 

 and Prof. \V. J. V. Osterhout, a botanist, and 

 published by the Rockefeller Institute of Medical 

 Research. This journal, which was referred to in 

 our issue of October 31 last, is 'devoted to the ex- 

 planation of life-phenomena on the basis of the physical 

 and chemical constitution of living matter," and first 

 appeared in September last. Its scope may, to some 

 extent, be illustrated by a number of reprints which 

 we have received ; they are of papers by Prof. Loeb, 

 some physico-chemical, some botanical in nature. 



In three papers on amphoteric colloids, which have 

 appeared in the first three numbers of the new journal. 

 Prof. Loeb has continued work previously published 

 by liim in the Journal of Biological Chemistry. Con- 

 trary to what is generally stated in the literature of 

 colloid chemistry, he concludes that the phvsical pro- 

 perties of gelatin near the point of neutrality are 

 affected only by thg cations of a neutral salt, and not 

 by its anions. "The error into which the colloid 

 chemists have fallen is due to the fact that they always 

 investigated the effect of a neutral salt on a protein 

 in the presence of the salt, while the writer took the 

 precaution to wash the excess of salt away after it 

 had time to act on the gelatin." Accordingly, a quan- 

 tity of finely powdered gelatin is left for one hour in 

 contact with a neutral salt solution of known con- 

 centration. The powder is then filtered off, and the 

 excess of salt removed by repeated . washing with 

 water. The gelatin is liquefied by heating to 50° C, 

 and diluted with water to make a i per cent, solution. 

 Then, for instance, the osmotic pressure of the solu- 

 tion is determined in a collodion bag. Treatment 

 with salts of a bivalent metal (MgCL, CaCL) does not 

 lead to an increase of osmotic pressure, but treatment 

 with sufficiently concentrated solutions of salts of 

 monovalent metals (NaCl, NaCNS, LiNO,, Na.SO,) 

 results in an increased osmotic pressure. When the 

 powdered gelatin is similarly treated with hydrochloric 

 acid of varying concentrations, it is found that about 

 N/256 HCl (which brings the gelatin to its isoelectric 

 point, /i, = 4-7) makes the total swelling, the osmotic 

 pressure, the conductivity, and the "alcohol number" 



minima. On the less acid side gelatin is regarded as 



_ -1- _ 



existing as a negative ion (e.g. gelatin-H or gelatin- 

 + ■ +' - 



Na) ; on the more acid side as a cation (gelatin-Cl or 



+ 

 gelatin^OH). 



In a later paper the author has determined the 

 amount of bromine in combination with gelatin after 

 treatment with hydrobromic acid of varying concen- 

 trations. He regards the curves of osmotic pressure 

 as an " unequivocal function " of the number of gelatin 



NO. 2601, VOL. 104] 



bromide molecules formed. Prof. Loeb has evidently 

 not seen the recent very careful and elaborate investiga- 

 tion, by Sorensen and his collaborators, of egg-albumin, 

 in the Comptes rendus of the Carlsberg laboratory. 

 A considerable section of this monograph deals 

 theoretically and practically with the osmotic pres- 

 sure of an amphoteric colloid of great purity in the 

 presence of electrolytes, and takes into account factors 

 which are not dealt with by Prof. Loeb's simple pro- 

 cedure. It will be interesting to see whether, after a 

 perusal of Sorensen 's monograph. Prof. Loeb still 

 maintains his somewhat sweeping criticism of colloid 

 chemists. 



The botanical reprints are concerned with the 

 mechanism of regeneration in Bryophyllum calvcinutn. 

 The leaves of this plant possess peculiar dormant 

 buds in each of the notches, which buds mav give 

 rise to roots and shoots so soon as the leaf is 

 separated from the plant. The chemical mechanism 

 of the process is dealt with in a paper in the Annates 

 de I'lnstitut Pasteur, and is a rare example of work 

 published in English in a French journal. In other 

 papers in the new journal the influence of the mass 

 of a leaf on the quantity of shoots regenerated in an 

 isolated piece of stem is measured, and the physio- 

 logical basis of polarity is discussed. It is suggested 

 that an inhibitory influence of the leaf upon shoot- 

 forrnation (as compared with root-formation) is due 

 to inhibitory substances secreted in the leaf, and 

 carried by the sap from the leaf towards the base of 

 the stem. 



/ETHER AND MATTER: BEING REMARKS 

 ON INERTIA, AND ON RADIATION, 

 AND ON THE POSSIBLE STRUCTURE 

 OF ATOMS.'L 



Part I. — Inertia. 

 \\l E are each of us flying through space at nineteen 

 ' * miles a second, probably much more. Nothing 

 is propelling us ; we continue to move by our own 

 inertia, simply because there is nothing to stop us; 

 Motion is a fundamental propertv of matter. No 

 piece of matter is at rest in the aether, the chances 

 are infinite against any piece having the particular 

 velocity zero; every bit is moving steadily at some 

 given speed, unless acted on by unbalanced force. 

 Then it is accelerated — changed either in speed or 

 direction, or both. 



As a matter of fact, we, like other bodies on the 

 earth, are acted on by tw-o slight, unbalanced forces — 

 one which makes us revolve round the earth once a 

 day, like a satellite ; the other which makes us revolve 

 round the sun once a year, like a planet or asteroid. 

 Our annual revolution is not because we are attached 

 to the earth; we are not attached, but revolve as 

 independent bodies, and would revolve in just the 

 same time and way if the earth were suddenly 

 obliterated ; only then we should find the diurnal 

 revolution transmuted into a twenty-four-hour rota- 

 tion round our own centres of gravity, and the 

 eccentricity of our annual orbit very slightly changed. 

 In any case, there is no propelling force, only a 

 residual radial force producing curvature of path. 



.\ railway train, or a ship moving steadily, is like- 

 wise subject to no resultant force. Propulsion and 

 resistance balance. The whole power of an engine, 

 after the start, is spent in overcoming friction. The 

 motion continues solely by inertia. Any steadily 

 moving body is an example of the first law of motion* 

 Yoif need not try to think of a bodv under no force 



^ Amplified from a discour':e d'-Iive'-ed at the Royal Institution on 

 Friday, February 28, 1919, by Sir Oliver J. Lodge, F.R.S. 



