D ECEMBEK I I. 1902] 



NA TURE 



i43 



known as to its chemical composition and as to the conditions 

 of its formation in digestion, there can be no doubt that trypto- 

 phane is a product of the disruption of the proteid molecule. 

 The point that had more particularly to be determined was 

 whether the substance giving the colour-reaction with chlorine 

 in these experiments is really tryptophane. The isolation of 

 tryptophane is a difficult process, and was not attempted. The 

 chemical identity of the substance is, however, established by 

 the fact that its chlorine compound was found to give the same 

 absorption spectrum as does that of tryptophane, namely, a band 

 in the green on the yellow side of the thallium line. — Mr. A. G. 

 Tansley gave an account of the relation of histogenesis to tissue 

 morphology, dealing with a few points bearing on the relation 

 of histogenesis at the apex of the stem in the Pteridophyta to 

 the morphology of the tissue regions in the adult stem. — Mr. 

 L. A. Boodle followed with a paper entitled "Stelar Structure 

 of Schizaja and other Ferns." 



Dublin. 

 Royal Irish Academy, November 10. — Prof. R. Atkinson, 

 president, in the chair. —Sir Robert Ball, F.R.S., communi- 

 cated a paper on the reflection of screws andfallied questions. 

 Let there be any system of straight lines and take any arbitrary 

 plane S. Let P be a point on one of the straight lines, and let 

 fall a perpendicular PT upon the plane S. Produce PT to P' 

 so that P'T = 1'T. Then the point P' is the reflection of P. If 

 we repeat this process for every point of the original system of 

 straight lines, we obtain the reflected figure. The fundamental 

 theorem is as follows : — The reflection of two reciprocal screws 

 also forms a reciprocal pair provided the signs of the pitches of 

 both screws be changed. From this we deduce the following 

 theorems : ( 1 ) The reflections of a set of coreciprocal screws also 

 form a set of coreciprocals ; (2) the reflection of an «-system of 

 screws is also an K-system. — Dr. R. F. Scharffread a paper on 

 the Atlantis problem. After dwelling upon the historical aspects 

 concerning the former existence of a continent beyond the 

 Strait of Gibraltar known to the ancients as " Atlantis," Dr. 

 Scharff referred to the attempts which had been made to solve 

 this problem from afaunistic point of view. He disagreed with 

 Dr. Wallace in his opinion that the fauna of the Atlantic 

 Islands had been derived from occasional means of dispersal, 

 and contended that the origin of their fauna was mainly due to 

 former land-connections with Portugal and Morocco. The 

 paper also dealt with the wider question of the existence of a 

 land-connection between the Old World and the New in the 

 same latitudes, the author maintaining that such a land-bridge 

 had persisted until Miocene times. — Prof. C. J. Joly read a 

 note on the multi-linear quaternion function in relation to pro- 

 jective geometry. When a quaternion is interpreted as a point- 

 symbol, the equation /=// represents the general homographic 

 transformation in space from one set of points q to another set 

 p,f being a linear quaternion function. Also if/' is the conju- 

 gate of/, the equations Sq(f+f')q = 0, Sq( /-/')</ = 0, represent 

 the general quadric surface and the general linear complex. 

 Starting from these results, which were communicated to the 

 Academy last year, the author proposes to consider the bilinear 

 function/!^). The equation p=f(eq) represents a homographic 

 transformation when e is regarded as a constant quaternion, 

 and by varying e, a four-system of homographic transformations 

 is obtained the properties of which may be easily studied. The 

 equation p=j\qq) represents the general quadratic transform- 

 ation. From a bilinear function f(pq), five other fundamental 

 functions may be obtained ; the first and second conjugates, viz. 

 the conjugates with respect to/ and to q ; the promutate f(qp), 

 and its first and second conjugates. The equation Sqf{qq)=o 

 represents the general cubic surface, and associaied with this 

 surface are systems of linear complexes Sefi,pq) = Se/lqp), just as 

 the linear complex and the quadric are connected with a 

 single function. The trilinear function f(pqr) leads to similar 

 results. In particular, if a and /; are two constant quaternions, 

 the equation p=f(a, b, q) represents the complete group of 

 linear transformations, any particular transformation being 

 determined by suitable values of a and b. 



Paris. 



Academy of Sciences, December I. — M. Bouquet de la 

 Grye in the chair. — On the temperature of inflammation and on 

 the combustion in oxygen of the three varieties of carbon, by 

 M. Henri Moissan. The temperature at which carbon enters 

 into active combustion with oxygen differs with the variety of 



NO. 1728, VOL. 67] 



carbon, being higher as the carbon is more polymerised. 

 Diamond becomes incandescent in oxygen between 8oo° and 

 S75°C, graphite between 650° and 700° C, amorphous carbon 

 between 300' and 50o°C., but in each case the visible combus- 

 tion is preceded by a stage during which the carbon is oxidised, 

 this action taking place with a velocity which decreases the 

 lower the temperature. Amorphous carbon is slowly oxidised 

 in either moist or dry oxygen at a temperature as low as 100° C. 

 — Experimental researches on adrenaline, by MM. Ch. Bouchard 

 and Henii Claude. Experiments carried out with rabbits 

 showed that the injection of 05 milligram of adrenaline per 

 kilogram of body weight, and in one case as little as o'2 milli- 

 gram, was rapidly fatal. The animals survived a dose of 

 01 mgr. per kilogram, and it was found possible, by gradually 

 increasing the amount injected, to diminish the susceptibility to 

 the toxic effects of the adrenaline. — The heart in its normal 

 state and during pregnancy, by MM. Ch. Bouchard and 

 Balthazard. The orthogonal projection of the heart was traced 

 by the aid of the X-rays and a fluorescent screen in forty-nine 

 subjects, and a preliminary table of the results is given. — Obser- 

 vations regarding physiological injections, by M. Yves Delage. 

 The injection of colouring matters such as ammonium carminate 

 and indigo carmine for localising with precision the excretory 

 functions is regarded as being likely to lead to fallacious con- 

 clusions. The colouring matters used are not normal excretion 

 products, and because in certain animals some of these sub- 

 stances are eliminated by the normal organs of secretion, it does 

 not follow that this is always the case. The line of argument 

 strictly followed out would even lead to the conclusion that the 

 nervous system is excretory because it fixes methylene blue. — 

 On the Laplace-Abel integral, by M. G. Miltag-Leffler. — On the 

 conditions necessary for the stability of equilibrium of a viscous 

 system, by M. P. Duhem. — The tracing of pressure curves, by 

 M. E. Vallier. — M. Deslandres was elected a member in the 

 section of astronomy in the place of the late M. Faye. — On 

 some consequences of certain developments in series analogous 

 with trigonometric expansions, by M. W. Stekloff. — On some 

 congruences with several unknowns, by M. R. Levavasseur. — 

 On a generalisation in continued fractions, by M. Auric. — On 

 uniform transcendentals, defined by differential equations of 

 the second order, by M. R. Liouville. — A method of evaluating 

 temperatures in the thermodynamic centigrade scale, by M. 

 Ponsot. The method suggested by M. Pellat requires the 

 simultaneous measurement of three magnitudes, the electro- 

 motive force of a thermoelement, the Peltier effect at one of 

 the junctions and the temperature of this junction in an 

 ordinary thermometric scale. The method suggested by the 

 author is simpler as the latter determination is dispensed 

 with. — The acceleration of gravity on the mean parallel, by 

 M. J. Collet. — On the composition of gaseous hydrates, by 

 M de Forcrand. By the application of the thermodynamical 

 method indicated in previous papers by the author, the 

 probable formula; of the hydrates of various gases are calculated ; 

 in nearly all cases, the hydrate has six molecules of water. — The 

 transformation of pyrophosphoric acid into orthophosphoric acid, 

 by M. H. Giran. By cooling syrupy pyrophosphoric acid down 

 to - io° C. for three months, the acid was obtained in the crystal- 

 lised form, and this was used for new thermochemical determin- 

 ations. — Manganese aluminate, by M. Em. Dufau. By heating 

 a mixture of alumina and oxide of manganese in the electric 

 furnace, an aluminate identical with that previously described 

 by Ebelmen is obtained, which on analysis proved to have the 

 composition Al 2 4 Mn. It formed clear yellow transparent 

 octahedral crystals, and although stable under conditions of 

 ordinary temperature, is readily oxidised when heated in con- 

 tact with air. — On the estimation of manganese, by M. H. 

 Baubigny. An account of the precautions required for the 

 estimation of manganese in acid solution by means of ammonium 

 persulphate. — The action of bromine and chlorine on the mono- 

 nitro-veratrols, by M. H. Cousin. In this paper, the constitutional 

 formulae of a certain number of trisubstituted derivatives of 

 pyrocatechol and its methyl esters are determined, and two 

 new nitro-derivatives are described. — On the reduction of acetol, 

 by M. Andre Kling. The action of several reducing agents upon 

 acetol was studied under various conditions, and the results lead 

 the author to conclude that the constitution usually assigned to 

 this compound is not correct, and that its constitution is better 



explained by the formula CHs ' C J 0H) / CH ' 2 .— The action of 



