December 12, [918] 



NATURE 



299 



which is ultimately abso 1- a slighl extent 



lared with K and Na. Anions are absorbed 

 initially in the ordei SO ,NO ,' I, which gives placi 

 later to the ordi r NOj.Cl.SO on aci ounl of the 

 comparative!} .vhich the sulphate ion 



is absorbed. fhe difference between nitrate and 

 chloride is sligh . ress can I"- laid on it. 



il w iih those of Ruhland, 

 Kitting, Pantanelli, and Troendle using diffi 



tods and ditTerenl experimental material. These 

 authors did not, however, distinguish between initial 

 1 01 and the position of final equili- 

 The position of final equilibrium appears to 

 bi governed bj some quite ditferenl property from 

 thai which determines the initial rate of intake. G, 

 Marinesco : Recherches anatomo-cliniques sur les 

 imes d'amputations douloureux. Nouvelles con- 

 tributions a I'dtude 1I1 la regeneration nerveuse et du 

 pisme. 

 Physical Society, Novembet 8 Prof. C. II. Lees, 

 lent, in the 1 hair. Prof. J. C. McLennan : 

 Low-voltage arcs in metallic vapours. The paper 

 describes experiments b\ Messrs. Hamer and 

 Kemp, students of the author's, at Toronto I ni- 

 l he experiments show that increasing 

 the temperature of the incandescent cathode 

 lowers tlit- voltage necessary to produce arcs in the 

 vapours of mercury, zinc, and cadmium. With limed 

 platinum cathodes arcing voltages were not obtained 

 -,> low a- with incandescent tungsten filaments. With 

 n\ il was found possible to strike arcs with 

 igi s as low as 475 volts, and to maintain them 

 s| \.ilis. Corresponding figures for cadmium 

 were 5 and 2 volts. To obtain these very low arcing 

 voltages it was necessary, to use intensely hot cathodes 

 ind a copious supply of highly heated metallic vapour. 

 With moderately heated incandescenl cathodes and a 

 moderate supply of metallic vapour the arcing voltages 

 were given by the quantum relation V=fex(i-5,S)/e, 



where ['5,S is the frequent \ of the shortest wave- 

 length in' the'v=i-5,S- mP series. Dr W. Wilson: 

 Relativity and gravitation, flu motion of a particle 

 .n a gravitational field i~ treated from the point of 

 view of the general theor) of relativity. It is shown 

 hal the equations of motion of the particle can be 

 --id in the following Hamiltonian form: 



rfr a.. ' 

 Ox. ^3H 

 dp,' 



win re /\ is the s component of the covariant 4-vector 

 momentum,*, the corresponding positional co-ordinate, 

 and r the Minkowskian "Eigenzeit." A short outline 

 of the Minkowskian theory "I relativity is included in 

 paper. C. R. Gibson: Experiments mi colour- 

 less. I'he apparatus shown consisted of a lan- 



■• produce a bright beam of white light and a 

 Coloured glass which could be slipped in front of it, 



- 10 rut out all the red rays. Various samples oi 

 ths and ribbons arranged in pairs, while 

 quite dissimilar when viewed l>\ the white light, ap- 

 ed perfect matches with the screen interposed, the 

 conditions then being similar to those in the case ol a 

 aid person. The author had found in experi- 

 menting with wools by this method that 111.11: colouri d 

 • unsuitable for the purposi mi accounl of 

 ilnis although no red light fill on them 

 from tin- apparatus, there was plenty ol red in tin 

 light reflected by the wools. In thi 1 ordei 



what tin- eeli. uis would appeal in the red-blind 

 man, it was necessary to have the filter between ih. 

 wool and the eye, and not simple between the source 

 hi and the wool. 



Royal Anthropological Institute, November -><>. — Prof. 

 \. Keith, past president, in the chair. Prof. F. G. 

 Parsons: Some points in tin- anthropology of German 

 prisoners of war. Owing to tin refusal ol the German 



military authorities to allow the Army to he used tm 

 anthropometric purposes, the anthropology ol Germany 

 •a, is probably less well worked out than that ol am 

 other European country. The author's present con- 

 tribution consisted of observations on 925 German 

 prisoners hi the war hospitals at Sutton and Daiiford, 

 and included the cephalic index, the facial index, the 



index of nigrescence, and the stature, though his 

 generalisations on the Last point were still incomplete; 

 as there existed a large mass of statistics in the hands 

 of the Government to be worked up. With regard to 



lihalic index, he found that the German avi 

 was X25, against the 7S2 of 227 British soldiers and 

 medical students, and that the German head was not 

 onlj actually shorter, but also actually broader than the 

 British. A "map of the distribution of the head-form 

 in German} showed thai the longest heads were found 

 in the north-west (Schleswig, Hanover, Westphalia, 

 and Khineland), while the shortest were in the south- 

 east: (Bavaria and Silesia). The lowest cephalic index 

 was that of Oldenburg (802), and the highest Bavaria 

 IS45). fhe facial index showed no approach to the 

 long Nordic face of England' and Scandinavia any- 

 where in Germany, while a map of the index of 

 nigrescence showed that the colouring of the people 

 had a general agreement with the head shape, the 

 lighter pigmentation accompanying the longer heads, 

 and vice versa. 



Paris. 

 Academy of Sciences, November t.S. — M. P. Painleve 

 in the chair.— M. J. A. Battandier was elected a 

 correspondant for the section of botany in succession 

 to tin late M. Grand'Eurv.— J. Droch : The complex 

 groups of rationality and the integration by quadra- 

 ture.— T. Lalesco : " Periodic polygonal functions.— 

 R. Gamier : Elementary solution of the problem of 

 the inversion of elliptic' functions.— R. Goormaghtigh : 

 Generalisation of Jamet's theorems on the curvature 

 of triangular curves, and of symmetrical tetrahedral 

 curves and surfaces. E. Belot : The laws of internal 

 density in theories of the sun.— E. Hildt : The estima- 

 tion of lactose. The use of benzene or phenol- 

 sulphonic acid is recommended for the hydrolysis. — 

 |. Lambert: The presence of a fasciole in a Procas- 



sidulid. P. Bertrand : Distinctive characters of the 



flora of the Coal Measures of Saint-Etienne and Rive- 



de-Gier. A. Piedallu : A new arrangement for the use 



of explosives applied to tree planting. Its advan- 

 tageous utilisation in the rapid reconstttution of 

 orchards devastated l>\ the enemy. The use of _ a 

 special cartridge is suggested for making holes suit- 

 able for i.e. planting. A. Grigaut and Fr. Moutier : 

 An attempt at the treatment of influenza by piasmo- 

 therapy (intravenous injections of plasma from a con- 

 valescent). The treatment is effective only if the injec- 

 tion is made before the third day of the attack.— 

 C. Richet : Comments on the preceding paper. 



November 25. — M. P. Painleve in the chair.— Gen. 



Bourgeois: A method of determining the direction and 



velocity of the wind in cloudy weather. Small bal- 



,„-,. let up. arranged so as to explode small 



s of melenite at regular intervals; sound 



I 1 1 plosions, .and the position in space 



, i -1 tonation 1 an be thus determine d. 



\1. \i iurii 1 Li blanc was elei b 6 a memb I th 

 division oi science applied to industry, and M. 

 corn spondanl foi the 31 1 tion ol botany 

 in sue. ?sion to the late Charles Eugene Bertrand.— 

 \l Petrovitch: The spectral determination of func- 



NO. 2563, VOL. I02] 



