April T, 1887] 



NA TURE 



537 



direction bids us more than ever to be cautious in taking 

 tlight on the wings of speculation. 



In the meantime we must content ourselves with the 

 use of working hypotheses in the various fields of inquiry ; 

 these we develop and modify as we go on, or, it may be, 

 discard in favour of others which for the time being seem 

 more in accordance with the facts before us. 



The triumphs of modern chemistry bear testimony that 

 faulty and incomplete as our present theories undoubtedly 

 are, our science is ever advancing. 



It is now well understood that the most important data 

 for the future extension of chemical theory will be derived 

 from the interpretation of the results of investigations 

 into the physical side of chemical phenomena. 



The examination of the optical properties of chemical 

 elements and compounds, the determination of thermo- 

 chemical constants, and the verification of physical con- 

 stants generally, are now pursued by a great number of 

 investigators. Of late also the experimental inquiry into 

 the connexion between electrical and chemical force is 

 becoming a fruitful field of research ; and we may hope 

 that further determinations of the coefficients of conduc- 

 tivity of electrolytes will before long lead to a clearer 

 perception of the intimate nature of chemical change. 



To pass in review the chemical work published during 

 the year, as some of my predecessors have done on 

 similar occasions, has now become an impossible task, 

 even supposing that the time at my disposal permitted 

 me to do so. I am, however, tempted to refer briefly to 

 a few results which strike me as particularly noteworthy. 



The work accomplished in thermo-chemistry is, as I 

 have already observed, very considerable, and thanks to 

 the patient labour of many workers the results thus 

 achieved are comprehensive enough to admit of a con- 

 sideration of their general bearings. In this respect I 

 wish to direct attention to the publication of Julius 

 Thomsen's fourth and concluding volume of " Thermo- 

 chemische Untersuchungen." This remarkable work is 

 entitled to the highest appreciation of all who realise the 

 manifold difficulties which beset the execution of thermo- 

 chemical investigation. But while referring to the many 

 highly important and remarkable deductions which the 

 author draws from his experiments, we cannot at the 

 same time help being struck by the many anomalous 

 results and startling conclusions which he arrives at. It 

 would seem that further determinations of the fundamen- 

 tal values, if possible by diflerent and varied experimental 

 methods, must be obtained before the full importance of 

 this work can be entirely realised. 



An important addition to our still very limited know- 

 ledge of the density of metallic elements in the gaseous 

 state has been made by V. Meyer and Mensching, who 

 have now succeeded in overcoming the great experimen- 

 tal difficulties formerly encountered in the determination 

 of the vapour-density of zinc. The molecule of zinc has 

 been found to be monatomic, like that of cadmium and 

 of mercury, the only two other metals the vapour-densities 

 of which are thus far known. 



The remarkable results recently published by Crookes 

 in his papers on the spectra of the so-called rare earths 

 are still fresh in our memor)*, and the ingenious applica- 

 tion he has made of the doctrine of evolution in this 

 speculation on the genesis of the elements has not failed 

 to attract the attention it deserves. 



The further investigations of the chemical and physical 

 properties of the new element germanium by Winkler, 

 Nilson, and Petterson have established its chemical 

 position, and the supposition that its proper place in the 

 periodic system is that of ekasilicon has been confirmed. 



Ladenburg's long-continued researches on conine ha\e 

 been crowned by success. He has effected its synthesis 

 and has shown that it is identical witha-propylpiperidine. 

 This must indeed be considered one of the most noteworthy 

 achievements in organic chemistry of the past year, inas- 



much as it is the first instance of the artificial formation 

 of an optically active natural alkaloid. 



Wallach found that the diazo-amido-compounds formed 

 from diazo-salts and piperidine are for the most part well- 

 characterised substances, and that when heated with con- 

 centrated hydrofluoric acid they yield the fluor-derivative 

 in almost theoretical proportions. He has prepared in this 

 way fluorbenzene, parafluortoluene, parafluornitrobenzene, 

 parafluoraniline, and fluorphenyl, &c. 



Studying the action of sodium on mixtures of ethers 

 such as oxalic and acetic ethers, \V. Wislicenus has dis- 

 covered a new and ready method of effecting the synthesis 

 of compound acids, and this reaction cannot fail to 

 become of great value. 



lirieger has succeeded in isolating a well-characterised 

 alkaloid from the liquid used for cultivating a certain 

 Bacillus which causes tetanus traumaticus in animals. 

 This substance, which the author calls tetanine, seems to 

 be the immediate cause of the toxic action of this Bacillus, 

 and thus for the first time a specific pathological effect of 

 a microbe has been traced to a well-defined chemical com- 

 pound produced or secreted in its life-process. 



Finally, I must also allude to the very remarkable 

 observation recently published by Liebreich which de- 

 monstrates the fact that under certain conditions chemical 

 reaction is retarded, and even altogether suspended. He 

 noticed that in a mixture of aqueous solutions of chloral 

 hydrate and sodium carbonate the formation of chloroform 

 does not take place uniformly throughout the liquid. For 

 instance, on performing the experiment in a test-tube there 

 appears immediately below the meniscus a sharply de- 

 fined space of 1-3 mm. thickness in which no reaction 

 takes place. Similar results were obtained when an aqueous 

 solution of iodic acid was mixed with sulphurous acid and 

 soluble starch. The inert space manifests itself on the 

 surface of the liquid which is in contact with the air or 

 separated from it by a thin membrane. In narrow tubes 

 the reaction is much more retarded, and it is altogether 

 suspended in capillary tubes. 



In my opinion this preliminary communication contains 

 the germs of a discovery in a new direction, and the 

 further study of the nature of these subtle influences which 

 bring about the phenomenon in question must lead to 

 important results. 



In bringing this report to a conclusion I must briefly 

 allude to a subject only indirectly connected with our 

 Society, viz. the progress made in the organisation of 

 technical education in this country, which, more par- 

 ticularly under the guidance and fostering care of the 

 City and Guilds of London Institute, is gradually making 

 its way. 



Most of you are aware that the President of this 

 Society is one of the ex officio members of the governing 

 and organising body of this Institute, and it may be 

 mentioned in passing that the regular attendance at the 

 frequent meetings of the various Committees and Sub- 

 Committees involves the necessity of devoting a by no 

 means inconsiderable amount of time to this honorary 

 office. 



The chief event to be recorded in this connexion is 

 the inauguration of the Central Institution which is to 

 fulfil the function of a Technical University or Poly- 

 technicum, and to afford higher scientific education to 

 the future owners, directors, managers, engineers of 

 manufacturing works, and the teachers in the various 

 branches of technology. This magnificent Institution 

 has now started on its career, and we have every reason 

 to think that before long its value will be fully recog- 

 nised by those who ought to take advantage of its exist- 

 ence. It is, however, unfortunate that the organisation 

 of this Institution has stopped short of the plans origin- 

 ally laid down, and has been not at once carried to 

 completion. Strange as it may appear, this is due to the 

 want of funds. The City and Guilds, in taking so pro- 



