June 16, 1887J 



NATURE 



167 



:ing place in the cell whilst generating a current. The 

 ctrode immersed in this oxidizable substance, like the zinc of 

 ordinary cell, would acquire the lower potential, and the 

 posed plate the higher potential ; i.e. the wire connected 

 th the latter would be the " positive pole " of the construction 

 reference to the external circuit. On trial, it has been found 

 it such is the case, and that in consequence a large variety 

 novel forms of cell becomes easy of construction. For 

 imple, sodium sulphite or potassium ferrocyanide solution 

 posed to chromic-sulphuric acid solution ; preferably with an 

 ermediate layer of some neutral salt solution, such as sodium 

 phate, to prevent the direct action of the two fluids on one 

 other. During the passage of a current, sodium sulphate or 

 tassium ferrocyanide is formed in quantity proportionate to 

 ; electricity passing, i.e. to the amount of silver thrown 

 wn in a silver voltameter included in the circuit ; whilst 

 romium sulphate is produced at the other side Various 

 alogous cells are described, in particular one where lead oxide 

 isolved in caustic soda is opposed to alkaline hypobromite : 

 this case lead dioxide is produced and separates out in the 

 id form ; and one where chromium sesquioxide dissolved in 

 .istic soda is opposed to chromium trioxiJe dissolved in sul- 

 uric acid ; here sodium chromate and chromium sulphate are 

 med, an E. M.F. about equal to that of a Daniell cell being 

 up. — The composition of Prussian blue and Turnbull's 

 le, by Mr. Edgar F. Reynolds. — Phlorizin, by Prof. E. H. 

 ;nnie. — P'urther notes on the chemical action of Bacterium 

 •ti, by Mr. Adrian J. Brown. — Note on the cellulose formed 

 Bacterium xylinuni, by Mr. Adrian J. Brown. — The 

 idation of ethyl alcohol in the presence of turpentine, by Mr. 

 E. Steedman, Williamstown, Victoria. 



Royal Microscopical Society, May 11. — Rev. Dr. 

 dlinger, F. R. S., President, in the chair. — Mr. Crisp called 

 ention to a number of slides of hair which Dr. Ondaatje, of 

 ylon, had forwarded to the Society with a request for infor- 

 ition as to its peculiarities of structure ; also to a donation by 

 ■. Deby of sixty-two slides, chiefly of Micro-Hymenoptera, 

 ich came from the collection of the late Mr. F. Smith. — Mr. 

 Mayall, Jun., said that he took it for granted that the Fellows 

 re interested in whatever concerned the history of the micro- 

 ipe, and would therefore be glad of any new facts which 

 ided to throw light upon the subject. He had lately come 

 I OSS evidence which showed that magnifying glasses were used 

 least as early as 1513-20, for, in the celebrated portrait of 

 X., by Raphael, the Pope is shown holding one in his hand, 

 e picture was painted between 1513 and 1520, as the Pope 

 5 elected in 15 13 and Raphael died in 1520. He brought to 

 meeting a large volume (lent for the purpose by Mr. 

 aritch) which contained an engraving of Raphael's portrait of 

 J3 X. During a recent visit to Florence he also paid some 

 ibntion to the microscopes which had been attributed to 

 'lileo. It was of course rather difficult to say in such matters 

 pat was really authentic and what was not. He could not, 

 vever, help noting that all the telescopes made in 1660, 

 ibout that time, had cardboard tubes, and wood or horn cells 

 the lenses, whereas these microscopes were made with sub- 

 itial brass body-tubes with strong and well-made screw 

 ads and firm tripod support. He could only say, therefore, 

 t if the microscope-makers had arrived at that stage of per- 

 ion.in Galileo's time, they had reached a point not attained 

 his successors until many years afterwards. — Mr. J. Mayall, 

 , also exhibited a microscope which had come from Japan. 

 vas made after one of the old upright tripod models and had 

 ng of inlaid silver ornamentation at both top and bottom. — 

 Maddox's paper, on the different tissues found in the muscles 

 1 mummy, was read. — Professor Bell gave an account of a 

 nt visit which he had paid to M. Pasteur's laboratory in 

 is. — Mr. Deby called attention to a series of double-stained 

 ions of the rare parasitical plant, Brugmansia Lowii, one of 

 Rafflesiae, but differing in its being hermaphrodite. It grows 

 the overground roots of a species of Cissus, and was col- 

 ed by him in 1884 in the Raritau range of mountains in 

 tral West Sumatra. The sections showed the development 

 lie plant from the time it begins to raise the bark of its host 

 minute tubercle up to the complete maturity of its ovules, 

 double staining allows of distinguishing between the tissues 

 ie parasite and of its host, which in unstained sections can- 

 be determined. The formation of the locula of the ovary is 

 remarkable, and partakes more of a fungoid growth than 

 lerogamic. 



Paris. 



Academy of Sciences, June 6. — M. Janssen in the chair. 

 — Researches on the density of sulphurous acid in the state 

 of liquid and of saturated vapour, by MM. L. Cailletet and 

 E. Mathias. Having already described the method employed 

 by them for determining the density of ethylene, of the prot- 

 oxide of nitrogen, and of carbonic acid as liquids and saturated 

 vapours, the authors here generalize their method by applying 

 it to the study of a substance (sulphurous acid), whose critical 

 point, approaching 156° C, is much higher than that of the 

 former gases. Their researches show that the densities of the 

 liquid and of the saturated vapour have a common limit, which 

 is opposed to the conclusion arrived at by Avenarius ; also that 

 the critical density is 0*520. — Heats of combustion, by MM. 

 Berthelot and Recoura. Continuing their studies of the heats 

 of combustion by the new calorimetric method, the authors 

 have determined the mean for glucose at 3762 calories; for 

 quinone, 6 '102 ; for napthalene, 9"688 ; for benzoic acid, 6 '345 ; 

 and for salicylic acid, 5 '326. These studies are being continued 

 with a view to determining the heat of combustion of liquid and 

 volatile bodies, and the measure of the heat of combustion of 

 pure carbon in its various states. Notwithstanding its funda- 

 mental importance for calculating the heats of formation of organic 

 compounds, this element has been neglected since the time 

 of Favre and Silbermann. — Heats of combustion, by MM. 

 Berthelot and Louguinine. Mean determinations are given 

 for several compounds, .such as napthalene, 9 "6961 calories ; 

 phenol, 7"8io5 ; benzoic acid, 6'322i ; cuminic acid, 7'5533 ; 

 quinone, 6 "06 13 ; hydroquinone, 6 "2295 ; pyrogallol, 5 '0262. 

 — A new endless tape odograph, by M. Marey. The 

 ingenious instrument here described has been prepared for 

 the purpose of automatically recording the velocity of 

 men walking or running with or without burdens, and under the 

 varying conditions of level or inclined, smooth or rugged track-, 

 with or against the wind, and so forth. It is especially applic- 

 able for determining the marching capacity of troops, as well as 

 the velocity of locomotives and other engines, of water and 

 atmospheric currents. — Action of oil on troubled waters, by 

 Admiral Clone. The author has studied the results of over two 

 hundred experiments, made especially in England and the 

 United States, and concludes that the question is now definitely 

 settled. There can no longer be any doubt that oil has a most 

 efficacious effect in calming storm-tossed waters, and thus saving 

 vessels in danger of foundering at sea. Fish oils appear to be 

 the best, mineral oils owing to their lightness the least effective, 

 but kitchen refuse of all sorts and similar substances floating 

 compactly on the surface, tend to produce the same result. — On 

 the character and results of the improved methods of amputation 

 lately introduced into hospitals, by M. Trelat. The author's 

 observations for the Charite and Necker Hospitals in Paris 

 show that since 1880, when the antiseptic methods came into 

 general use, the mortality under all kinds of amputations has 

 fallen from 50 and upwards to an average of about 15 per cent. 

 — On the density of the celestial vault, in relation to the radiant- 

 points, by M. Alexis de Tillo. According to their right ascen- 

 sions the 1315 radiant-points of the northern hemisphere are 

 shown to be disposed in such a way as to make it evident 

 that the regions traversed by the Milky Way (o°-90° and 

 270°-36o°) have a perceptibly greater meteoric density than the 

 others (90°-i8o° and i8o"-27o°) which lie mainly beyond that 

 stellar zone. — On the melotrope, a new musical apparatus, by 

 M. J. Carpentier. This instrument is intended to serve as a 

 complement to the recently described melograph, the automatic 

 records of which it faithfully reproduces on any piano. But it 

 may also be so adjusted as to constitute itself an independent 

 instrument suitable for the performance of automatic music gener- 

 ally. — Action of an electro-static field on a variable current, by 

 M. Vaschy. It is shown that in a magnetic field of vaiying 

 intensity a closed conductor placed in this field is traversed by 

 induced currents, and in general there arises in each point of 

 the space an electric force capable of being calculated. In other 

 words, the variations of the magnetic field develop a true electro- 

 static field exercising a mechanical action on the electrified 

 bodies. In virtue of the principle of equilibrium between action 

 and reaction, the latter must react on the magnets or variable 

 currents to which is due the magnetic field. — On the conductibility 

 of abnormal salts and of acids in extended solution, by M. E, 

 Bouty. The author's previous conclusion is here confirmed, 

 that in respect of their conductibility these acids differ greatly 

 from each other, not even excepting sulphuric, nitric, and hydro- 



