624 



NATURE 



{April 29, 1880 



gives 41 paths, nearly all of which were traced on August 21-23, 

 1879. 



IV. On October 15, 1S79, the sky was watched for eleven 

 hours (6h. 30m. to 17I1. 30m.), and of the 127 shooting-stais 

 seen during that lengthy observation, 21 were slow meteors from 

 a radiant point at 31 + 9 , but the position was not well de- 

 fined. I had seen several meteors from the same region on the 

 previous night, and on the 20th, when the sky was again favour- 

 able, I recorded 10 others, making 37 in all from this shower in 

 the south of Aries. They were generally faint, with rather 

 short paths, and decidedly slow. The same radiant was seen 

 by Major Tupman in 1869, October 13, at 28° + 10", and Mr. 

 Corder has distinguished a series of October positions in Aries 

 and Pisces. The diagram (IV. ) includes 42 paths observed by 

 me in the years 1876-79, but chiefly in 1879. 



V. At about the middle of August, 1877, a few rapid meteors 

 were traced from a radiant in Musca at 40 + 28°, and in the 

 following year, while noting the progress of the Perseids, I 

 recorded several fine meteors, leaving streaks, and with paths 

 averaging 40 . The radiant was evidently on the horizon, and 

 the directions of the meteors, which in several instances were 

 very exactly observed and mapped, indicated the point 44° + 25° 

 as the diverging focus of the shower. With the object of 

 further investigating it, I examined the observations made at the 

 epoch of the Perseids, by the Italians in 1872 and by Zezioli in 

 1867-70, and found many meteors conforming to this shower 

 of Muscids, which had already been detected by Weiss in 

 1869, August 11, 46^° + 23i°, and August 12, 41$° + 24°. In 

 this region, between Musca and the east extremity of Aries, 

 there are many successive showers during the four months from 

 August to November. Early in August, when the first display 

 is perceptible, the meteors are very swift, with unusually long 

 paths, and seldom without streaks ; but in October and Novem- 

 ber the motions are generally slow, and the phosphorescent 

 streaks, forming so persistent a feature of the earlier displays, 

 have given way to occasional trains of ashy sparks. The August 

 shower above referred to merits description, as supplying some 

 fine long meteors in the mornings of August. Thirty-eight paths 

 are shown in the diagram, several of which are notable on account 

 of inordinate length. 



The several showers here mentioned, being apparently of little 

 less importance than the Orionids, Geminids, Taurids, &c, will 

 no doubt be frequently seen in future years ; and it seems desir- 

 able to select them from the mass of feeble systems now ascer- 

 tained, as affording displays of more than ordinary richness. 



W. F. Denning 



CHEMICAL SOCIETY— ANNIVERSARY 



MEETING 



TyE take the following extract from the address, at the Anni- 



** versary Meeting, of the Chemical Society on March 30. 



by the president, Dr. De la Rue : — 



Although since my last term of office I have not been pre- 

 cisely in a sleepy hollow, like that described by Washington 

 Irving, nevertheless my thoughts have been mainly absorbed 

 by other branches of science, and I found myself, on returning 

 to this chair, very much in the same perplexity as Rip ^ an 

 Winkle when he awoke in the Kaatskill Mountains after his 

 long sleep. 



So rapid has been the progress of our science, that much of 

 the aspect of chemical thought has altered in the interval ; old 

 and once familiar bodies have not only changed their nomencla- 

 ture, but new and unfamiliar individuals and families have 

 crowded into the greatly extended domain of chemistry. The 

 very elements which are looked upon as most stable are now 

 considered to be in a critical position, and liable at any moment 

 to dissociation ; for it is only a few months ago that the minds 

 of chemists were disturbed by the announcement that spectro- 

 scopic evidence afforded by the sun and stars tended to show that 

 the so-called elements were in reality compound bodies. Even 

 if we reserve our judgment on this point, we can no longer assert 

 that the light emitted from the so-called elements, when incan- 

 descent or vaporised, is characterised by certain definite wave- 

 lengths. Moreover, we learn that a well-known German chemist, 

 Professor V. Meyer, has actually succeeded in dissociating the 

 halogens, chlorine, bromine, and iodine. The results which he 

 and his coadjutors have obtained appear to leave little doubt that 

 such is actually the case, and wc must await the outcome of then- 

 continued labours with intense interest. 



As regards the spectrum itself, we can no longer attribute 

 certain specific functions and properties to different parts of it ; 

 for Captain Abney has shown that every part of the spectrum 

 acts actinically, and he even goes so far as to hold out a prospect 

 of Becquerel's beautiful discovery being further extended, so as 

 to produce permanent photographs of the spectrum in its natural 

 colours. In his Bakerian lecture to the Royal Society, Captain 

 Abney has made known his method of preparing a form of silver 

 bromide, sensitive not only to the ultra-violet and the whole 

 visible spectrum, but also to the infra-red rays, and has presented 

 to that Society his magnificent map of the infra-red spectrum. 

 It is difficult to overrate the value of this discovery, and it may 

 be expected that important results will accrue from the investiga- 

 tion of the infra-red absorption spectra of various substances. 

 Indeed, Captain Abney has already informed me of his progress 

 in this direction. The importance of photography, not only as 

 affording a means of investigation, but as a method of permanently 

 recording observations which may be dealt with at leisure, thus 

 affording the means of accurate measurement, in such hands as 

 those of Dewar, Liveing, and Abney, cannot be too highly 

 prized. 



A problem which had long baffled all efforts, the artificial 

 production of the diamond, is said to have been solved. Mr. 

 Hannay's communication on the subject is so vague, however, 

 that it is impossible to pronounce any opinion on it. The 

 observations on the solubility of solids in gases, which led Mr. 

 Ilannay to attempt to crystallise carbon, and which are described 

 in a recent communication to the Royal Society by Messrs. 

 Hannay and Hogarth, are of great interest, and most important 

 results will doubtless be obtained by an extension of these 

 experiments. 



The necessity for further information on the subject of the 

 behaviour of various substances, and especially of mixtures 

 under great pressure, is well shown by the recent remarkable 

 observations of Cailletet, that on compressing a mixture of five 

 volumes of carbon dioxide and one volume of air, the former at 

 first liquefies ; but that as the pre-sure is increased to 150-200 

 atmospheres, the meniscus of the liquid carbon dioxide becomes 

 plane, and is gradually effaced, until finally the liquid wholly 

 disappears, apparently dissolving in the gas. 



Mr. Ansdell's papers on the " Physical Constants of Liquid 

 Acetylene and Liquid Hydrogen Chloride," as determined with 

 the aid of the Cailletet apparatus in the laboratory of the Royal 

 Institution, are valuable contributions to our knowledge of 

 chemical physics, and appear to furnish the interesting result, 

 that the volume of the fluid and gas are equal at the critical 

 point in the case of the latter substance. 



Another investigation in chemical physics of great interest is 

 that recently published by Briihl, who has considerably extended 

 the observations of Gladstone, Landolt, and others, on the 

 refractive indices of carbon-compounds. The introduction of 

 a new method of calculating the results by which the influence 

 of dispersion is eliminated, has led him to the discovery of an 

 apparently very simple relation between chemical constitution 

 and refractive power. 



The extraordinary diligence of chemists who apply themselves 

 to the investigation of carbon-compounds has also reaped a rich 

 harvest of results. It would be impossible for me to consider 

 the progress of this branch of chemisti y in detail, but I cannot 

 help noticing how rapidly the more complex bodies, such as the 

 alkaloids and the carbo-hydrates, are being forced to yield up 

 the secret of their constitution, which has so long been w ithheld. 

 The synthesis of /satin by Claisen and Shad well, and the 

 researches of Baeyer in the indigo-group, must, it would seem, 

 ere long result in the discovery of a method for the artificial 

 manufacture of this colouring matter. 



Ladenburg's success in preparing the alkaloid atropine from 

 Tropine and Tropic acid, the two substances which it furnishes 

 when decomposed by hydration, is no doubt the first step towards 

 the synthesis of an alkaloid. Great advances have been made 

 in unravelling the constitution of the bases of the Pyridine and 

 Picoline series, and much light has been thrown thereby on the 

 constitution of nicotine and the Cinchona alkaloids. Moreover, 

 important additions have been made to our knowledge of starch. 

 It is remarkable, also, that a number of new facts have been 

 brought to light tending to prove that the symbolic system at 

 present employed to represent the constitution of carbon- 

 compounds is insufficient. 



The year has not passed by without announcements ot new 

 members of the family of Elements. 



One of the most inter- 



