January 15, 1903] 



Mature 



263 



tleydweiller's recent experiments. The reacting substances 

 are suspended freely, but in separate vessels, at one 

 extremity of a torsion balance the beam of which lies in the 

 meridian, and at noon or midnight the reaction is started by 

 contrivances described in the paper. A deflection of the beam 

 is looked for, or a change in its angular velocity. A loss or gain 

 of mass involves the energy associated with the inertia of matter 

 moving with the earth's velocity, and on the assumption either 

 that the momentum or kinetic energy is conserved, ihe possi- 

 bility arises that a mechanical effect on the whole mass may 

 become apparent. The results so far are negv.ive, that 

 is, no gross mechanical effect has been obtained. If such 

 exists, it is not of a magnitude corresponding to the weight- 

 change observed by Heydiveiller. Several of Heydweiller's 

 reactions were repeated. The method of observation is being 

 improved. — Improved polarising vertical illuminator, by J. 

 Joly, F. R S. This is an improvement on a method previously 

 described by the author of observing sections of transparent 

 rock-forming minerals by light which has been twice trans- 

 mitted through the section, the object being to increase the 

 colour differences due to birefringence and so increase the 

 discriminative value of the phenomena. — Prof. T. Johnson 

 exhibited specimens of swede-rot, due to Pnoma, received Irom 

 County Down and not hitherto observed in Ireland. The 

 fungus agrees in its characters with Phoma Brassicae, Thiim., 

 causing a rot of fodder cabbages in France. It appears iden- 

 tical, including the pink colour associated with the conidia 

 escaping from the pyenidia, with the Phoma described by 

 Potteras causing a turnip-rot in the north of Eigland. 



Royal Irish Academy, January 12.— Prof. Atkinson, 

 president, in the chair. — Prof. C. f. Joly read a paper on the 

 quadratic screw system: a study of a family of quadratic 

 complexes. He believes that the memoir contains a lairly full 

 account of the arrangement of the screws in this important 

 family. The method employed is that indicated in the author's 

 note on systems of rays in the appendix to the new edition 

 of Hamilton's " Elements of (Quaternions." 



Edinburgh. 



Royal Society, December 15, 1902. — Dr. Munro in the 

 chair. — Prof. James Walker and Mr. A. J. Robertson com- 

 municated a paper on freezing-point depression in electrolytic 

 solutions. The interest of the paper lay in the method adopted 

 and in the great delicacy of manipulation required. In all 

 experimental attempts to measure the freezing-point depression 

 of solutions, the divergence of the actually observed temperature 

 is known to depend upon the difference between the true 

 freezing point and the " convergence temperature," and on the 

 rate at which ice is formed or dissolved. The.true freezing- 

 point will be registered if either the convergence temperature 

 and the true equilibrium temperature are identical, or the rate 

 of formation or fusion of ice infinitely great. The experimental 

 method adopted was that suggested by the latter condition. 

 For a given quantity of solution, the more ice taken and the 

 finer its division the more rapidly will the equilibrium tempera- 

 ture be restored after any disturbance, and the more closely 

 will the apparent and true freezing points coincide. In the 

 experiments described, the quantity of ice used was never less 

 than 12 per cent, of the weight of the solution. The concen- 

 tration of the solution was determined immediately after the 

 determination of the freezing-point depression by filtering off a 

 quantity of the liquid and analysing it. A complete experiment 

 consisted in first determining these quantities for an approxi- 

 mately decinormal solution of acetic acid, and immediately 

 thereafter the same magnitudes for a solution of a good electro- 

 lyte of approximately the same freezing point. The validity of 

 the method was first tested by experiments with malonic acid 

 which obeys Ostwald's dilution law ; and then freezing-point 

 experiments were made on certain strong electrolytes for which 

 previous observers had obtained results which were not accor- 

 dant with the ionisation values obtained from the conductivities. 

 Taking into account all the difficulties and disturbing factors in 

 experiments of this kind, the authors conclude that their results 

 tend to increase confidence in the methods of exact cryoscopy. — 

 Dr. G. A. Gibson gave a preliminary statement as regards the 

 condition of the blood in cyanosis. He showed that the blood 

 is always of high specific gravity, while the amount of haemo- 

 globin is increased. The number of the red blood corpuscles is 

 almost invariably raised, sometimes to a very great degree, and 



NO. I733, VOL. 67] 



the white blood corpuscles are usually increased to a consider- 

 able extent. The object of the communication was to show 

 that, although in cyanosis the different elements of the blood 

 are increased throughout the whole vascular system, yet the 

 increase is not uniform, as it is greatest in the veins, less in the 

 capillaries and least in the arteries. Some years ago, the author 

 brought forward the hypothesis that this increase in the blood 

 elements is compensatory and is produced by the lessened 

 destruction of the blood in consequence of diminished oxygen- 

 ation. This explanation appears to be borne out by the tact 

 that there is an increase in arteries, capillaries and veins, but 

 the results of the present investigation show that any method 

 based upon the assumption of a uniform condition of the blood 

 throughout the system is fallacious. The concluding part of the 

 paper was devoted to the effect of oxygen in cases of cyanosis, 

 and the result of its employment thus far is to show that its 

 effect upon the blood in cyanosis is inappreciable. — Dr. Gibson 

 also gave a lantern demonstration on cases of acromegaly and 

 gigantism. 



Paris. 

 Academy of Sciences, January 5. — M. Albert Gaudry in 

 the chair. — Remarks on the composition of the gases from the 

 fumeroles of Mont Pelee, and on the origin of volcanic pheno- 

 mena, by M. Armand Gautier. — The results of the analyses of the 

 gases from the volcanic fumeroles of Mont Pelee recently made 

 by M. Moissan are compared with the analyses by the author 

 of gases extracted from igneous rocks by heating to a red heat 

 in a vacuum. The gases are qualitatively the same and of 

 similar composition quantitatively, and a theory of volcanic 

 action is deduced from these considerations. — A new examin- 

 ation of the objections of M. Leduc relating to the proportion of 

 free hydrogen in air, by M. Armand Gautier. It is held that 

 M. Leduc has not succeeded in answering the objections 

 raised by the author in his last note, and in particular 

 it is pointed out that air which has passed over 10 centi- 

 metres of red-hot copper oxide cannot be assumed to have 

 been freed from all traces of combustible gases, since a portion 

 of the hydrogen and methane in the air escape combus- 

 tion even after passing over three times this length of 

 glowing copper oxide. — On the use of the stereoscope in topo- 

 graphy and in astronomy, by M. le Colonel Laussedat — On 

 some facts of endomorphism observed in the ruins of St. Pierre. 

 Martinique, by M. A. Lacroix. A description of the phen >- 

 mena which have taken place on the contact of iron materials 

 with fused silicates, and showing the facility with which a 

 volcanic rock, accidentally fused and kept in contact with divers 

 materials, attacks them and transforms them both chemically 

 and mineralogically.— On universal functions In space, by M. A. 

 Korn. — On a new classification of the modes of nomographic 

 representation of equations with any number of variables, by 

 M. Maurice d'Ocagne.-A new method p( testing rails, by 

 M. Ch. Fremont Three modes of testing' rails are in actual 

 use : by extension, flexure under a statical charge, and flexure 

 by shock. In the testing by flexure under a sudden 

 load, which is of the highest practical importance, it is 

 assumed that the rails are homogeneous, a condition which 

 is by no means fulfilled in practice, and it is this 

 want of homogeneity which is frequently the cause of the 

 discordance between the results of the trial and those of 

 practice. A method of testing is described in which this defect 

 is avoided. — On a plane representation of space and its applica- 

 tion to graphical statics, by M. B. Mayor. — On the dielectric 

 cohesion of gases, by M. E. Bouty. When the pressure of the 

 gas is of the order of some centimetres of mercury, the critical 

 field necessary to overcome the dielectric cohesion of the gas is 

 a linear function of the pressure ; at very low pressures, it is not 

 the field, but the difference of total potential corresponding '.o 

 the thickness of the gaseous column which remains constant. — 

 On the statical work of muscle, by M. Charles Henry — On 

 the absolute value of the magnetic elements 01 January 1, 

 1903, by M. Th. Moureaux. A table is given showing the 

 absolute values and secular variation of the magnetic elements 

 at the Val-Joyeux Observatory. — On the activity of some 

 salts of the rare earths as producing oxidation, by M. 

 Andre Job. A solution of cerous acetate, although per- 

 fectly stable towards air, rapidly oxidises a solution 

 of hydroquinone to quinhydrone. The acetate of 

 lanthanum behaves similarly, from which the conclusion is 

 drawn that a peroxide of lanthanum must be capable of exist- 

 ence. — On two new methods of synthesis of the oxyphosphinic 



