Feb. 27, 1890] 



NATURE 



407 



molten electrolytes, and upon the K. M. F. at the surface of con- 

 act of a metal and a melted salt, by M. Lucien Poincarc. The 

 author finds the E.M.F.'s in this case to be nearly the same as 

 those found by M. Bouty (Comptes rendus, t, xc. p. 217) in the 

 case of saturated solutions. — Electrolysis by igneous fusion of 

 the oxide and fluoride of aluminium, by M. Adolphe Miiiet. 

 The author presents the result of three years' work on the 

 electrolysis of the fused oxide and fluoride of aluminium, in a 

 table which gives the quantity of metal obtained as a function of 

 the time and of the quantity of electricity used. — Note by MM. 

 P. Ilautefeuille and A. Perrey, on the silico-glucinates of soda. 

 In a preceding note, the authors have described a number of 

 silico-glucinates of potash, obtained by heating together mixtures 

 of silica, glucina, and the alkali, with neutral vanadate of potash. 

 They now have applied the same method of mineralization with 

 mixtures containing soda, heating to about 800°. Five forms, of 

 different composition, have been thus obtained. Substituting 

 tungstate for vanadate of soda, two species of crystals have 

 been obtained, corresponding in composition with two of 

 those obtained with vanadate as mineralizing agent. — Upon 

 the rdle of foreign bodies in iron and steel ; the relation 

 between their atomic volumes and the allotropic transformations 

 of iron, by M. F. Osmond. Prof. W. C. Roberts-Austen, 

 studying the effect of minute percentages of foreign elements 

 upon the mechanical properties of gold, found a relation between 

 the results obtained and the position in the periodic table of the 

 introduced elements, and has predicted a similar phenomenon in 

 the case of iron. Reviewing his former work in the light of this 

 new idea, the author has found the prediction to be verified. 

 Shortly, it may be said that foreign bodies of small atomic 

 volume tend to cause iron to assume or remain in that of its 

 molecular forms in which it has itself the smaller atomic volume, 

 bodies of gr^at atomic volume produce the opposite effect. — M. 

 J. Ville, on dioxyphosphinic and oxyphosphinous acids. In 

 two preceding notes {Comptes rendus, t. cvii. p. 659, t. cix. 

 p. 71), and in the present communication, it is shown that by 

 the reaction of aldehydes upon hypophosphorous acid, two new 

 classes of acids, have been obtained, with the general formula; : — 



/(R . CH . CH) 

 (I) PO( (R . CH . OH) 



NOW 



^OH 



(2) PO(-(R— CH . OH). 

 ^OH 



— Dibromo-carballylic acid, by M. E. Guinochet. This acid 

 has been obtained by the reactions of 4 equivalents of bromine 

 upon one equivalent of aconitic acid in a sealed tube, heated for 

 thirty-six hours to Ii5°-i20°. — Estimation of uric acid in urine 

 by means of a hot solution of hypobromite of soda, by M. Bayrac. 

 The principle of the method consists in separating the uric acid 

 from the urea and "creatinin present by alcohol, and the titration 

 of the isolated acid with sodic hypobromite at 90°-ioo°. Results 

 are said to be as exact as those obtained by the best known 

 methods, while the process takes much less time. — Researches 

 upon the pathogenic microbes in the filtered waters of the Rhone, 

 by MM. Lortet and Despeignes. — Upon the nutrition ofthefungus 

 of the mugiiet, by MM. Gedrges'Lhiossierand Gabriel Roux. A 

 complete study of the mineral, carbohydrate, and nitrogenous 

 foods required and the substances produced by this fungus is given. 

 — The perception of luminous radiations by theskin, as exemplified 

 by the blind Proteus of the grottos of Carniola, by M. Raphael 

 Dubois. By a number of experiments upon Proteus anguinis, 

 the author demonstrates that the sensibility of its skin to light is 

 about half of the sensibility of its rudimentary eyes, and further 

 that tliis sensibility varies With the colour of the light employed, 

 being greatest for yellow light. — The wax-organs and the secre- 

 tion of wax in the bee, by M. G. Carlet. The author's researches 

 lead him to conclude: (i) the wax is produced by the 4 last 

 ventral arches of the abdomen ; (2) it is secreted by an epithelial 

 membrane and not by the cuticular layer of these arches, nor by 

 the intra-abdominal glands ; (3) this secretory membrane lies 

 between the cuticular layer and the lining membrane of the 

 antero-lateral part of the ventral arch ; (4) the wax traverses the 

 cuticular layer and accumulates on its outer surface. — Experi- 

 mental plant cultivation in high altitudes, note by M. Gaston 

 Bonnier. The modifications produced in Alpine plants by the 

 climate have been studied and some general conclusions drawn, 

 among which the most interesting is : " For the same extent of leaf 

 surface, the assimilation is much more considerable in Alpine 

 plants than in those of lower stations, on account of the 

 greater thickness of (he palisade tissue and the abundance of 

 chlorophyll." 



Berlin. 



Physiological Society, January 31. — Prof, du Bois-Key- 

 mond, President, in the chair. — Dr. Grabower spoke on root- 

 area of the motor nerves of the laryngeal muscles. — Prof. 

 Munk made a further communication on the subject of 

 the cortical visual areas. His earlier researches on the extir- 

 pation of these areas had shown that the retina may be re- 

 garded as spatially projected on to the visual area in such a 

 way that its external portion corresponds to the external part of 

 the visual area of the same side, while the inner portion corre- 

 sponds to the inner part of the area of the opposite side, and the 

 middle portion to the middle part of the visual area of the opposite 

 side. The upper half of the retina corresponds to the anterior 

 part of the visual area, and the lower half to the posterior. 

 More recently. Prof. Schafer, of London, has found that, when 

 the visual areas are stimulated electrically, movements result 

 which are confined entirely to the eyes ; when the anterior part 

 of the area is stimulated, the eye is turned downwards and 

 towards the opposite side ; and when the posterior part is 

 stimulated, the movement is similarly towards the opposite side, 

 but now upwards. When, however, the central part of the 

 area is stimulated, the result is merely a movement towards the 

 opposite side. It was shown by the speaker, as the result of a 

 large number of experiments on dogs which he had performed in 

 conjunction with Dr. Obregici, that these movements are not 

 dependent on the stimulation of any motor centres or upon any 

 ordinary reflex movements, but that they are really movements 

 which accompany visual sensations. They were shown by care- 

 ful analysis to result in the directing of the eye towards that 

 point in space into which the visual perception is referred when- 

 ever any definite point of the retina is stimulated by light, the 

 point stimulated in this case being the corresponding part of the 

 electrically stimulated visual area. Thus when the anterior 

 part of the area is stimulated, the lower portion of the retina is 

 stimulated, the resulting visual image is consequently referred 

 out upwards, and the eyes accordingly also move upwards and 

 towards the opposite side. Similarly for stimulations of other 

 parts of the visual area. These experimental stimulations hence 

 afford an evidence of the detailed spatial projection of the retina 

 on to the visual areas, which is as certain and even more con- 

 vincing than the evidence obtained from localized extirpations of 

 the areas. They further permitted of a more certain delimitation 

 of the visual areas than had been possible in the earlier experi- 

 ments. It is impossible to enter here into the many interesting 

 details of these experiments, or to give any account of the lengthy 

 discussion which followed Prof. Munk's communication. 



Physical Society, February 7. — Prof. Kundt, President, in 

 the chair. — Dr. Budde spoke on the very rapid rotation of a 

 solid body, possessed of three unequal moments of inertia, about 

 a fixed point. He developed very fully the equations which 

 hold good for this motion, and dealt, at the end of his communi- 

 cation, with the physical experiments which might be performed 

 in order to test the equations. — Dr. Feussner spoke on the 

 methods which are employed at the Government Physico-tech- 

 nical Institute for the measurement of electrical resistances. 

 He exhibited and explained the several instruments used, point- 

 ing out that in their arrangement the greatest importance must 

 be attached to the very accurate measurements of temperature. 

 For this purpose the wires are wound upon metallic cylinders in 

 order to provide for the rapid cooling of the wires as they are 

 warmed by the passage of the current : these are then submerged 

 in petroleum, whose temperature is recorded by a thermometer 

 immersed in the liquid, which is itself kept constantly stirred, 

 German-silver wires have shown themselves to be unsuited for 

 the purposes of constructing the standard resistances, since their 

 resistance increases regularly with lapse of time ; neither could 

 this increase be done away with by heating the wires until they 

 were quite soft. This tendency was attributed to the occurrence 

 of a gradual crystallization, which depended chiefly upon the zinc 

 in the alloy. On this account an alloy of copper and nickel was 

 employed, which is known commercially as "patent nickel," 

 and examined as to its suitability. Wires made of this alloy 

 possess a very low temperature-coefficient, and were found to be 

 .almost absolutely constant after being heated to 100° C. If 

 they are kept for some time after they are made and wound, and 

 are then heated, they may be used as standards for comparison. 

 Several other alloys were also tried, as, for instance, various 

 combinations of copper and manganese. The speaker described 

 the experimental measurements made with these wires, and 

 stated that up to 30 per cent, of manganese, above which amount 



